prototype.htm

/*  Prototype JavaScript framework, version 1.5.0_rc1
 *  (c) 2005 Sam Stephenson <sam@conio.net>
 *
 *  Prototype is freely distributable under the terms of an MIT-style license.
 *  For details, see the Prototype web site: http://prototype.conio.net/
 *
/*--------------------------------------------------------------------------*/

var Prototype = {
	Version: '1.5.0_rc1',
	ScriptFragment: '(?:<script.*?>)((\n|\r|.)*?)(?:<\/script>)',

	emptyFunction: function() {
	},
	K: function(x) {
		return x
	}
}

var Class = {
	create: function() {
		return function() {
			this.initialize.apply(this, arguments);
		}
	}
}

var Abstract = new Object();

Object.extend = function(destination, source) {
	for (var property in source) {
		destination[property] = source[property];
	}
	return destination;
}

Object.extend(Object, {
	inspect: function(object) {
		try {
			if (object == undefined) return 'undefined';
			if (object == null) return 'null';
			return object.inspect ? object.inspect() : object.toString();
		} catch (e) {
			if (e instanceof RangeError) return '...';
			throw e;
		}
	},

	keys: function(object) {
		var keys = [];
		for (var property in object)
			keys.push(property);
		return keys;
	},

	values: function(object) {
		var values = [];
		for (var property in object)
			values.push(object[property]);
		return values;
	},

	clone: function(object) {
		return Object.extend({}, object);
	}
});

Function.prototype.bind = function() {
	var __method = this, args = $A(arguments), object = args.shift();
	return function() {
		return __method.apply(object, args.concat($A(arguments)));
	}
}

Function.prototype.bindAsEventListener = function(object) {
	var __method = this, args = $A(arguments), object = args.shift();
	return function(event) {
		return __method.apply(object, [( event || window.event)].concat(args).concat($A(arguments)));
	}
}

Object.extend(Number.prototype, {
	toColorPart: function() {
		var digits = this.toString(16);
		if (this < 16) return '0' + digits;
		return digits;
	},

	succ: function() {
		return this + 1;
	},

	times: function(iterator) {
		$R(0, this, true).each(iterator);
		return this;
	}
});

var Try = {
	these: function() {
		var returnValue;

		for (var i = 0; i < arguments.length; i++) {
			var lambda = arguments[i];
			try {
				returnValue = lambda();
				break;
			} catch (e) {
			}
		}

		return returnValue;
	}
}

/*--------------------------------------------------------------------------*/

var PeriodicalExecuter = Class.create();
PeriodicalExecuter.prototype = {
	initialize: function(callback, frequency) {
		this.callback = callback;
		this.frequency = frequency;
		this.currentlyExecuting = false;

		this.registerCallback();
	},

	registerCallback: function() {
		this.timer = setInterval(this.onTimerEvent.bind(this), this.frequency * 1000);
	},

	stop: function() {
		if (!this.timer) return;
		clearInterval(this.timer);
		this.timer = null;
	},

	onTimerEvent: function() {
		if (!this.currentlyExecuting) {
			try {
				this.currentlyExecuting = true;
				this.callback(this);
			} finally {
				this.currentlyExecuting = false;
			}
		}
	}
}
Object.extend(String.prototype, {
	gsub: function(pattern, replacement) {
		var result = '', source = this, match;
		replacement = arguments.callee.prepareReplacement(replacement);

		while (source.length > 0) {
			if (match = source.match(pattern)) {
				result += source.slice(0, match.index);
				result += (replacement(match) || '').toString();
				source = source.slice(match.index + match[0].length);
			} else {
				result += source,source = '';
			}
		}
		return result;
	},

	sub: function(pattern, replacement, count) {
		replacement = this.gsub.prepareReplacement(replacement);
		count = count === undefined ? 1 : count;

		return this.gsub(pattern, function(match) {
			if (--count < 0) return match[0];
			return replacement(match);
		});
	},

	scan: function(pattern, iterator) {
		this.gsub(pattern, iterator);
		return this;
	},

	truncate: function(length, truncation) {
		length = length || 30;
		truncation = truncation === undefined ? '...' : truncation;
		return this.length > length ?
			   this.slice(0, length - truncation.length) + truncation : this;
	},

	strip: function() {
		return this.replace(/^\s+/, '').replace(/\s+$/, '');
	},

	stripTags: function() {
		return this.replace(/<\/?[^>]+>/gi, '');
	},

	stripScripts: function() {
		return this.replace(new RegExp(Prototype.ScriptFragment, 'img'), '');
	},

	extractScripts: function() {
		var matchAll = new RegExp(Prototype.ScriptFragment, 'img');
		var matchOne = new RegExp(Prototype.ScriptFragment, 'im');
		return (this.match(matchAll) || []).map(function(scriptTag) {
			return (scriptTag.match(matchOne) || ['', ''])[1];
		});
	},

	evalScripts: function() {
		return this.extractScripts().map(function(script) {
			return eval(script)
		});
	},

	escapeHTML: function() {
		var div = document.createElement('div');
		var text = document.createTextNode(this);
		div.appendChild(text);
		return div.innerHTML;
	},

	unescapeHTML: function() {
		var div = document.createElement('div');
		div.innerHTML = this.stripTags();
		return div.childNodes[0] ? div.childNodes[0].nodeValue : '';
	},

	toQueryParams: function() {
		var pairs = this.match(/^\??(.*)$/)[1].split('&');
		return pairs.inject({}, function(params, pairString) {
			var pair = pairString.split('=');
			var value = pair[1] ? decodeURIComponent(pair[1]) : undefined;
			params[decodeURIComponent(pair[0])] = value;
			return params;
		});
	},

	toArray: function() {
		return this.split('');
	},

	camelize: function() {
		var oStringList = this.split('-');
		if (oStringList.length == 1) return oStringList[0];

		var camelizedString = this.indexOf('-') == 0
				? oStringList[0].charAt(0).toUpperCase() + oStringList[0].substring(1)
				: oStringList[0];

		for (var i = 1, len = oStringList.length; i < len; i++) {
			var s = oStringList[i];
			camelizedString += s.charAt(0).toUpperCase() + s.substring(1);
		}

		return camelizedString;
	},

	inspect: function(useDoubleQuotes) {
		var escapedString = this.replace(/\\/g, '\\\\');
		if (useDoubleQuotes)
			return '"' + escapedString.replace(/"/g, '\\"') + '"';
		else
			return "'" + escapedString.replace(/'/g, '\\\'') + "'";
	}
});

String.prototype.gsub.prepareReplacement = function(replacement) {
	if (typeof replacement == 'function') return replacement;
	var template = new Template(replacement);
	return function(match) {
		return template.evaluate(match)
	};
}

String.prototype.parseQuery = String.prototype.toQueryParams;

var Template = Class.create();
Template.Pattern = /(^|.|\r|\n)(#\{(.*?)\})/;
Template.prototype = {
	initialize: function(template, pattern) {
		this.template = template.toString();
		this.pattern = pattern || Template.Pattern;
	},

	evaluate: function(object) {
		return this.template.gsub(this.pattern, function(match) {
			var before = match[1];
			if (before == '\\') return match[2];
			return before + (object[match[3]] || '').toString();
		});
	}
}

var $break = new Object();
var $continue = new Object();

var Enumerable = {
	each: function(iterator) {
		var index = 0;
		try {
			this._each(function(value) {
				try {
					iterator(value, index++);
				} catch (e) {
					if (e != $continue) throw e;
				}
			});
		} catch (e) {
			if (e != $break) throw e;
		}
	},

	all: function(iterator) {
		var result = true;
		this.each(function(value, index) {
			result = result && !!(iterator || Prototype.K)(value, index);
			if (!result) throw $break;
		});
		return result;
	},

	any: function(iterator) {
		var result = false;
		this.each(function(value, index) {
			if (result = !!(iterator || Prototype.K)(value, index))
				throw $break;
		});
		return result;
	},

	collect: function(iterator) {
		var results = [];
		this.each(function(value, index) {
			results.push(iterator(value, index));
		});
		return results;
	},

	detect: function (iterator) {
		var result;
		this.each(function(value, index) {
			if (iterator(value, index)) {
				result = value;
				throw $break;
			}
		});
		return result;
	},

	findAll: function(iterator) {
		var results = [];
		this.each(function(value, index) {
			if (iterator(value, index))
				results.push(value);
		});
		return results;
	},

	grep: function(pattern, iterator) {
		var results = [];
		this.each(function(value, index) {
			var stringValue = value.toString();
			if (stringValue.match(pattern))
				results.push((iterator || Prototype.K)(value, index));
		})
		return results;
	},

	include: function(object) {
		var found = false;
		this.each(function(value) {
			if (value == object) {
				found = true;
				throw $break;
			}
		});
		return found;
	},

	inject: function(memo, iterator) {
		this.each(function(value, index) {
			memo = iterator(memo, value, index);
		});
		return memo;
	},

	invoke: function(method) {
		var args = $A(arguments).slice(1);
		return this.collect(function(value) {
			return value[method].apply(value, args);
		});
	},

	max: function(iterator) {
		var result;
		this.each(function(value, index) {
			value = (iterator || Prototype.K)(value, index);
			if (result == undefined || value >= result)
				result = value;
		});
		return result;
	},

	min: function(iterator) {
		var result;
		this.each(function(value, index) {
			value = (iterator || Prototype.K)(value, index);
			if (result == undefined || value < result)
				result = value;
		});
		return result;
	},

	partition: function(iterator) {
		var trues = [], falses = [];
		this.each(function(value, index) {
			((iterator || Prototype.K)(value, index) ?
			 trues : falses).push(value);
		});
		return [trues, falses];
	},

	pluck: function(property) {
		var results = [];
		this.each(function(value, index) {
			results.push(value[property]);
		});
		return results;
	},

	reject: function(iterator) {
		var results = [];
		this.each(function(value, index) {
			if (!iterator(value, index))
				results.push(value);
		});
		return results;
	},

	sortBy: function(iterator) {
		return this.collect(function(value, index) {
			return {value: value, criteria: iterator(value, index)};
		}).sort(function(left, right) {
			var a = left.criteria, b = right.criteria;
			return a < b ? -1 : a > b ? 1 : 0;
		}).pluck('value');
	},

	toArray: function() {
		return this.collect(Prototype.K);
	},

	zip: function() {
		var iterator = Prototype.K, args = $A(arguments);
		if (typeof args.last() == 'function')
			iterator = args.pop();

		var collections = [this].concat(args).map($A);
		return this.map(function(value, index) {
			return iterator(collections.pluck(index));
		});
	},

	inspect: function() {
		return '#<Enumerable:' + this.toArray().inspect() + '>';
	}
}

Object.extend(Enumerable, {
	map:	 Enumerable.collect,
	find:	Enumerable.detect,
	select:  Enumerable.findAll,
	member:  Enumerable.include,
	entries: Enumerable.toArray
});
var $A = Array.from = function(iterable) {
	if (!iterable) return [];
	if (iterable.toArray) {
		return iterable.toArray();
	} else {
		var results = [];
		for (var i = 0; i < iterable.length; i++)
			results.push(iterable[i]);
		return results;
	}
}

Object.extend(Array.prototype, Enumerable);

if (!Array.prototype._reverse)
	Array.prototype._reverse = Array.prototype.reverse;

Object.extend(Array.prototype, {
	_each: function(iterator) {
		for (var i = 0; i < this.length; i++)
			iterator(this[i]);
	},

	clear: function() {
		this.length = 0;
		return this;
	},

	first: function() {
		return this[0];
	},

	last: function() {
		return this[this.length - 1];
	},

	compact: function() {
		return this.select(function(value) {
			return value != undefined || value != null;
		});
	},

	flatten: function() {
		return this.inject([], function(array, value) {
			return array.concat(value && value.constructor == Array ?
								value.flatten() : [value]);
		});
	},

	without: function() {
		var values = $A(arguments);
		return this.select(function(value) {
			return !values.include(value);
		});
	},

	indexOf: function(object) {
		for (var i = 0; i < this.length; i++)
			if (this[i] == object) return i;
		return -1;
	},

	reverse: function(inline) {
		return (inline !== false ? this : this.toArray())._reverse();
	},

	reduce: function() {
		return this.length > 1 ? this : this[0];
	},

	uniq: function() {
		return this.inject([], function(array, value) {
			return array.include(value) ? array : array.concat([value]);
		});
	},

	inspect: function() {
		return '[' + this.map(Object.inspect).join(', ') + ']';
	}
});
var Hash = {
	_each: function(iterator) {
		for (var key in this) {
			var value = this[key];
			if (typeof value == 'function') continue;

			var pair = [key, value];
			pair.key = key;
			pair.value = value;
			iterator(pair);
		}
	},

	keys: function() {
		return this.pluck('key');
	},

	values: function() {
		return this.pluck('value');
	},

	merge: function(hash) {
		return $H(hash).inject($H(this), function(mergedHash, pair) {
			mergedHash[pair.key] = pair.value;
			return mergedHash;
		});
	},

	toQueryString: function() {
		return this.map(function(pair) {
			return pair.map(encodeURIComponent).join('=');
		}).join('&');
	},

	inspect: function() {
		return '#<Hash:{' + this.map(function(pair) {
			return pair.map(Object.inspect).join(': ');
		}).join(', ') + '}>';
	}
}

function $H(object) {
	var hash = Object.extend({}, object || {});
	Object.extend(hash, Enumerable);
	Object.extend(hash, Hash);
	return hash;
}
ObjectRange = Class.create();
Object.extend(ObjectRange.prototype, Enumerable);
Object.extend(ObjectRange.prototype, {
	initialize: function(start, end, exclusive) {
		this.start = start;
		this.end = end;
		this.exclusive = exclusive;
	},

	_each: function(iterator) {
		var value = this.start;
		while (this.include(value)) {
			iterator(value);
			value = value.succ();
		}
	},

	include: function(value) {
		if (value < this.start)
			return false;
		if (this.exclusive)
			return value < this.end;
		return value <= this.end;
	}
});

var $R = function(start, end, exclusive) {
	return new ObjectRange(start, end, exclusive);
}

var Ajax = {
	getTransport: function() {
		return Try.these(
				function() {
					return new XMLHttpRequest()
				},
				function() {
					return new ActiveXObject('Msxml2.XMLHTTP')
				},
				function() {
					return new ActiveXObject('Microsoft.XMLHTTP')
				}
				) || false;
	},

	activeRequestCount: 0
}

Ajax.Responders = {
	responders: [],

	_each: function(iterator) {
		this.responders._each(iterator);
	},

	register: function(responderToAdd) {
		if (!this.include(responderToAdd))
			this.responders.push(responderToAdd);
	},

	unregister: function(responderToRemove) {
		this.responders = this.responders.without(responderToRemove);
	},

	dispatch: function(callback, request, transport, json) {
		this.each(function(responder) {
			if (responder[callback] && typeof responder[callback] == 'function') {
				try {
					responder[callback].apply(responder, [request, transport, json]);
				} catch (e) {
				}
			}
		});
	}
};

Object.extend(Ajax.Responders, Enumerable);

Ajax.Responders.register({
	onCreate: function() {
		Ajax.activeRequestCount++;
	},

	onComplete: function() {
		Ajax.activeRequestCount--;
	}
});

Ajax.Base = function() {
};
Ajax.Base.prototype = {
	setOptions: function(options) {
		this.options = {
			method:	   'post',
			asynchronous: true,
			contentType:  'application/x-www-form-urlencoded',
			parameters:   ''
		}
		Object.extend(this.options, options || {});
	},

	responseIsSuccess: function() {
		return this.transport.status == undefined
				|| this.transport.status == 0
				|| (this.transport.status >= 200 && this.transport.status < 300);
	},

	responseIsFailure: function() {
		return !this.responseIsSuccess();
	}
}

Ajax.Request = Class.create();
Ajax.Request.Events =
['Uninitialized', 'Loading', 'Loaded', 'Interactive', 'Complete'];

Ajax.Request.prototype = Object.extend(new Ajax.Base(), {
	initialize: function(url, options) {
		this.transport = Ajax.getTransport();
		this.setOptions(options);
		this.request(url);
	},

	request: function(url) {
		var parameters = this.options.parameters || '';
		if (parameters.length > 0) parameters += '&_=';

		/* Simulate other verbs over post */
		if (this.options.method != 'get' && this.options.method != 'post') {
			parameters += (parameters.length > 0 ? '&' : '') + '_method=' + this.options.method;
			this.options.method = 'post';
		}

		try {
			this.url = url;
			if (this.options.method == 'get' && parameters.length > 0)
				this.url += (this.url.match(/\?/) ? '&' : '?') + parameters;

			Ajax.Responders.dispatch('onCreate', this, this.transport);

			this.transport.open(this.options.method, this.url,
					this.options.asynchronous);

			if (this.options.asynchronous)
				setTimeout(function() {
					this.respondToReadyState(1)
				}.bind(this), 10);

			this.transport.onreadystatechange = this.onStateChange.bind(this);
			this.setRequestHeaders();

			var body = this.options.postBody ? this.options.postBody : parameters;
			this.transport.send(this.options.method == 'post' ? body : null);

			/* Force Firefox to handle ready state 4 for synchronous requests */
			if (!this.options.asynchronous && this.transport.overrideMimeType)
				this.onStateChange();

		} catch (e) {
			this.dispatchException(e);
		}
	},

	setRequestHeaders: function() {
		var requestHeaders =
				['X-Requested-With', 'XMLHttpRequest',
						'X-Prototype-Version', Prototype.Version,
						'Accept', 'text/javascript, text/html, application/xml, text/xml, */*'];

		if (this.options.method == 'post') {
			requestHeaders.push('Content-type', this.options.contentType);

			/* Force "Connection: close" for Mozilla browsers to work around
						* a bug where XMLHttpReqeuest sends an incorrect Content-length
						* header. See Mozilla Bugzilla #246651.
						*/
			if (this.transport.overrideMimeType)
				requestHeaders.push('Connection', 'close');
		}

		if (this.options.requestHeaders)
			requestHeaders.push.apply(requestHeaders, this.options.requestHeaders);

		for (var i = 0; i < requestHeaders.length; i += 2)
			this.transport.setRequestHeader(requestHeaders[i], requestHeaders[i + 1]);
	},

	onStateChange: function() {
		var readyState = this.transport.readyState;
		if (readyState != 1)
			this.respondToReadyState(this.transport.readyState);
	},

	header: function(name) {
		try {
			return this.transport.getResponseHeader(name);
		} catch (e) {
		}
	},

	evalJSON: function() {
		try {
			return eval('(' + this.header('X-JSON') + ')');
		} catch (e) {
		}
	},

	evalResponse: function() {
		try {
			return eval(this.transport.responseText);
		} catch (e) {
			this.dispatchException(e);
		}
	},

	respondToReadyState: function(readyState) {
		var event = Ajax.Request.Events[readyState];
		var transport = this.transport, json = this.evalJSON();

		if (event == 'Complete') {
			try {
				(this.options['on' + this.transport.status]
						|| this.options['on' + (this.responseIsSuccess() ? 'Success' : 'Failure')]
						|| Prototype.emptyFunction)(transport, json);
			} catch (e) {
				this.dispatchException(e);
			}

			if ((this.header('Content-type') || '').match(/^text\/javascript/i))
				this.evalResponse();
		}

		try {
			(this.options['on' + event] || Prototype.emptyFunction)(transport, json);
			Ajax.Responders.dispatch('on' + event, this, transport, json);
		} catch (e) {
			this.dispatchException(e);
		}

		/* Avoid memory leak in MSIE: clean up the oncomplete event handler */
		if (event == 'Complete')
			this.transport.onreadystatechange = Prototype.emptyFunction;
	},

	dispatchException: function(exception) {
		(this.options.onException || Prototype.emptyFunction)(this, exception);
		Ajax.Responders.dispatch('onException', this, exception);
	}
});

Ajax.Updater = Class.create();

Object.extend(Object.extend(Ajax.Updater.prototype, Ajax.Request.prototype), {
	initialize: function(container, url, options) {
		this.containers = {
			success: container.success ? $(container.success) : $(container),
			failure: container.failure ? $(container.failure) :
					 (container.success ? null : $(container))
		}

		this.transport = Ajax.getTransport();
		this.setOptions(options);

		var onComplete = this.options.onComplete || Prototype.emptyFunction;
		this.options.onComplete = (function(transport, object) {
			this.updateContent();
			onComplete(transport, object);
		}).bind(this);

		this.request(url);
	},

	updateContent: function() {
		var receiver = this.responseIsSuccess() ?
					   this.containers.success : this.containers.failure;
		var response = this.transport.responseText;

		if (!this.options.evalScripts)
			response = response.stripScripts();

		if (receiver) {
			if (this.options.insertion) {
				new this.options.insertion(receiver, response);
			} else {
				Element.update(receiver, response);
			}
		}

		if (this.responseIsSuccess()) {
			if (this.onComplete)
				setTimeout(this.onComplete.bind(this), 10);
		}
	}
});

Ajax.PeriodicalUpdater = Class.create();
Ajax.PeriodicalUpdater.prototype = Object.extend(new Ajax.Base(), {
	initialize: function(container, url, options) {
		this.setOptions(options);
		this.onComplete = this.options.onComplete;

		this.frequency = (this.options.frequency || 2);
		this.decay = (this.options.decay || 1);

		this.updater = {};
		this.container = container;
		this.url = url;

		this.start();
	},

	start: function() {
		this.options.onComplete = this.updateComplete.bind(this);
		this.onTimerEvent();
	},

	stop: function() {
		this.updater.options.onComplete = undefined;
		clearTimeout(this.timer);
		(this.onComplete || Prototype.emptyFunction).apply(this, arguments);
	},

	updateComplete: function(request) {
		if (this.options.decay) {
			this.decay = (request.responseText == this.lastText ?
						  this.decay * this.options.decay : 1);

			this.lastText = request.responseText;
		}
		this.timer = setTimeout(this.onTimerEvent.bind(this),
				this.decay * this.frequency * 1000);
	},

	onTimerEvent: function() {
		this.updater = new Ajax.Updater(this.container, this.url, this.options);
	}
});
function $() {
	var results = [], element;
	for (var i = 0; i < arguments.length; i++) {
		element = arguments[i];
		if (typeof element == 'string')
			element = document.getElementById(element);
		results.push(Element.extend(element));
	}
	return results.reduce();
}

document.getElementsByClassName = function(className, parentElement) {
	var children = ($(parentElement) || document.body).getElementsByTagName('*');
	return $A(children).inject([], function(elements, child) {
		if (child.className.match(new RegExp("(^|\\s)" + className + "(\\s|$)")))
			elements.push(Element.extend(child));
		return elements;
	});
}

/*--------------------------------------------------------------------------*/

if (!window.Element)
	var Element = new Object();

Element.extend = function(element) {
	if (!element) return;
	if (_nativeExtensions) return element;

	if (!element._extended && element.tagName && element != window) {
		var methods = Object.clone(Element.Methods), cache = Element.extend.cache;

		if (element.tagName == 'FORM')
			Object.extend(methods, Form.Methods);
		if (['INPUT', 'TEXTAREA', 'SELECT'].include(element.tagName))
			Object.extend(methods, Form.Element.Methods);

		for (var property in methods) {
			var value = methods[property];
			if (typeof value == 'function')
				element[property] = cache.findOrStore(value);
		}
	}

	element._extended = true;
	return element;
}

Element.extend.cache = {
	findOrStore: function(value) {
		return this[value] = this[value] || function() {
			return value.apply(null, [this].concat($A(arguments)));
		}
	}
}

Element.Methods = {
	visible: function(element) {
		return $(element).style.display != 'none';
	},

	toggle: function(element) {
		element = $(element);
		Element[Element.visible(element) ? 'hide' : 'show'](element);
		return element;
	},

	hide: function(element) {
		$(element).style.display = 'none';
		return element;
	},

	show: function(element) {
		$(element).style.display = '';
		return element;
	},

	remove: function(element) {
		element = $(element);
		element.parentNode.removeChild(element);
		return element;
	},

	update: function(element, html) {
		$(element).innerHTML = html.stripScripts();
		setTimeout(function() {
			html.evalScripts()
		}, 10);
		return element;
	},

	replace: function(element, html) {
		element = $(element);
		if (element.outerHTML) {
			element.outerHTML = html.stripScripts();
		} else {
			var range = element.ownerDocument.createRange();
			range.selectNodeContents(element);
			element.parentNode.replaceChild(
					range.createContextualFragment(html.stripScripts()), element);
		}
		setTimeout(function() {
			html.evalScripts()
		}, 10);
		return element;
	},

	inspect: function(element) {
		element = $(element);
		var result = '<' + element.tagName.toLowerCase();
		$H({'id': 'id', 'className': 'class'}).each(function(pair) {
			var property = pair.first(), attribute = pair.last();
			var value = (element[property] || '').toString();
			if (value) result += ' ' + attribute + '=' + value.inspect(true);
		});
		return result + '>';
	},

	recursivelyCollect: function(element, property) {
		element = $(element);
		var elements = [];
		while (element = element[property])
			if (element.nodeType == 1)
				elements.push(Element.extend(element));
		return elements;
	},

	ancestors: function(element) {
		return $(element).recursivelyCollect('parentNode');
	},

	descendants: function(element) {
		element = $(element);
		return $A(element.getElementsByTagName('*'));
	},

	previousSiblings: function(element) {
		return $(element).recursivelyCollect('previousSibling');
	},

	nextSiblings: function(element) {
		return $(element).recursivelyCollect('nextSibling');
	},

	siblings: function(element) {
		element = $(element);
		return element.previousSiblings().reverse().concat(element.nextSiblings());
	},

	match: function(element, selector) {
		element = $(element);
		if (typeof selector == 'string')
			selector = new Selector(selector);
		return selector.match(element);
	},

	up: function(element, expression, index) {
		return Selector.findElement($(element).ancestors(), expression, index);
	},

	down: function(element, expression, index) {
		return Selector.findElement($(element).descendants(), expression, index);
	},

	previous: function(element, expression, index) {
		return Selector.findElement($(element).previousSiblings(), expression, index);
	},

	next: function(element, expression, index) {
		return Selector.findElement($(element).nextSiblings(), expression, index);
	},

	getElementsBySelector: function() {
		var args = $A(arguments), element = $(args.shift());
		return Selector.findChildElements(element, args);
	},

	getElementsByClassName: function(element, className) {
		element = $(element);
		return document.getElementsByClassName(className, element);
	},

	getHeight: function(element) {
		element = $(element);
		return element.offsetHeight;
	},

	classNames: function(element) {
		return new Element.ClassNames(element);
	},

	hasClassName: function(element, className) {
		if (!(element = $(element))) return;
		return Element.classNames(element).include(className);
	},

	addClassName: function(element, className) {
		if (!(element = $(element))) return;
		Element.classNames(element).add(className);
		return element;
	},

	removeClassName: function(element, className) {
		if (!(element = $(element))) return;
		Element.classNames(element).remove(className);
		return element;
	},

	observe: function() {
		Event.observe.apply(Event, arguments);
		return $A(arguments).first();
	},

	stopObserving: function() {
		Event.stopObserving.apply(Event, arguments);
		return $A(arguments).first();
	},

// removes whitespace-only text node children
	cleanWhitespace: function(element) {
		element = $(element);
		for (var i = 0; i < element.childNodes.length; i++) {
			var node = element.childNodes[i];
			if (node.nodeType == 3 && !/\S/.test(node.nodeValue))
				Element.remove(node);
		}
		return element;
	},

	empty: function(element) {
		return $(element).innerHTML.match(/^\s*$/);
	},

	childOf: function(element, ancestor) {
		element = $(element),ancestor = $(ancestor);
		while (element = element.parentNode)
			if (element == ancestor) return true;
		return false;
	},

	scrollTo: function(element) {
		element = $(element);
		var x = element.x ? element.x : element.offsetLeft,
				y = element.y ? element.y : element.offsetTop;
		window.scrollTo(x, y);
		return element;
	},

	getStyle: function(element, style) {
		element = $(element);
		var value = element.style[style.camelize()];
		if (!value) {
			if (document.defaultView && document.defaultView.getComputedStyle) {
				var css = document.defaultView.getComputedStyle(element, null);
				value = css ? css.getPropertyValue(style) : null;
			} else if (element.currentStyle) {
				value = element.currentStyle[style.camelize()];
			}
		}

		if (window.opera && ['left', 'top', 'right', 'bottom'].include(style))
			if (Element.getStyle(element, 'position') == 'static') value = 'auto';

		return value == 'auto' ? null : value;
	},

	setStyle: function(element, style) {
		element = $(element);
		for (var name in style)
			element.style[name.camelize()] = style[name];
		return element;
	},

	getDimensions: function(element) {
		element = $(element);
		if (Element.getStyle(element, 'display') != 'none')
			return {width: element.offsetWidth, height: element.offsetHeight};

		// All *Width and *Height properties give 0 on elements with display none,
		// so enable the element temporarily
		var els = element.style;
		var originalVisibility = els.visibility;
		var originalPosition = els.position;
		els.visibility = 'hidden';
		els.position = 'absolute';
		els.display = '';
		var originalWidth = element.clientWidth;
		var originalHeight = element.clientHeight;
		els.display = 'none';
		els.position = originalPosition;
		els.visibility = originalVisibility;
		return {width: originalWidth, height: originalHeight};
	},

	makePositioned: function(element) {
		element = $(element);
		var pos = Element.getStyle(element, 'position');
		if (pos == 'static' || !pos) {
			element._madePositioned = true;
			element.style.position = 'relative';
			// Opera returns the offset relative to the positioning context, when an
			// element is position relative but top and left have not been defined
			if (window.opera) {
				element.style.top = 0;
				element.style.left = 0;
			}
		}
		return element;
	},

	undoPositioned: function(element) {
		element = $(element);
		if (element._madePositioned) {
			element._madePositioned = undefined;
			element.style.position =
			element.style.top =
			element.style.left =
			element.style.bottom =
			element.style.right = '';
		}
		return element;
	},

	makeClipping: function(element) {
		element = $(element);
		if (element._overflow) return;
		element._overflow = element.style.overflow || 'auto';
		if ((Element.getStyle(element, 'overflow') || 'visible') != 'hidden')
			element.style.overflow = 'hidden';
		return element;
	},

	undoClipping: function(element) {
		element = $(element);
		if (!element._overflow) return;
		element.style.overflow = element._overflow == 'auto' ? '' : element._overflow;
		delete element._overflow;
		return element;
	}
}

// IE is missing .innerHTML support for TABLE-related elements
if (document.all) {
	Element.Methods.update = function(element, html) {
		element = $(element);
		var tagName = element.tagName.toUpperCase();
		if (['THEAD','TBODY','TR','TD'].indexOf(tagName) > -1) {
			var div = document.createElement('div');
			switch (tagName) {
				case 'THEAD':
				case 'TBODY':
					div.innerHTML = '<table><tbody>' + html.stripScripts() + '</tbody></table>';
					depth = 2;
					break;
				case 'TR':
					div.innerHTML = '<table><tbody><tr>' + html.stripScripts() + '</tr></tbody></table>';
					depth = 3;
					break;
				case 'TD':
					div.innerHTML = '<table><tbody><tr><td>' + html.stripScripts() + '</td></tr></tbody></table>';
					depth = 4;
			}
			$A(element.childNodes).each(function(node) {
				element.removeChild(node)
			});
			depth.times(function() {
				div = div.firstChild
			});

			$A(div.childNodes).each(
					function(node) {
						element.appendChild(node)
					});
		} else {
			element.innerHTML = html.stripScripts();
		}
		setTimeout(function() {
			html.evalScripts()
		}, 10);
		return element;
	}
}

Object.extend(Element, Element.Methods);

var _nativeExtensions = false;

if (!window.HTMLElement && /Konqueror|Safari|KHTML/.test(navigator.userAgent)) {
	/* Emulate HTMLElement, HTMLFormElement, HTMLInputElement, HTMLTextAreaElement,
	and HTMLSelectElement in Safari */
	['', 'Form', 'Input', 'TextArea', 'Select'].each(function(tag) {
		var klass = window['HTML' + tag + 'Element'] = {};
		klass.prototype = document.createElement(tag ? tag.toLowerCase() : 'div').__proto__;
	});
}

Element.addMethods = function(methods) {
	Object.extend(Element.Methods, methods || {});

	function copy(methods, destination) {
		var cache = Element.extend.cache;
		for (var property in methods) {
			var value = methods[property];
			destination[property] = cache.findOrStore(value);
		}
	}

	if (typeof HTMLElement != 'undefined') {
		copy(Element.Methods, HTMLElement.prototype);
		copy(Form.Methods, HTMLFormElement.prototype);
		[HTMLInputElement, HTMLTextAreaElement, HTMLSelectElement].each(function(klass) {
			copy(Form.Element.Methods, klass.prototype);
		});
		_nativeExtensions = true;
	}
}

var Toggle = new Object();
Toggle.display = Element.toggle;

/*--------------------------------------------------------------------------*/

Abstract.Insertion = function(adjacency) {
	this.adjacency = adjacency;
}

Abstract.Insertion.prototype = {
	initialize: function(element, content) {
		this.element = $(element);
		this.content = content.stripScripts();

		if (this.adjacency && this.element.insertAdjacentHTML) {
			try {
				this.element.insertAdjacentHTML(this.adjacency, this.content);
			} catch (e) {
				var tagName = this.element.tagName.toLowerCase();
				if (tagName == 'tbody' || tagName == 'tr') {
					this.insertContent(this.contentFromAnonymousTable());
				} else {
					throw e;
				}
			}
		} else {
			this.range = this.element.ownerDocument.createRange();
			if (this.initializeRange) this.initializeRange();
			this.insertContent([this.range.createContextualFragment(this.content)]);
		}

		setTimeout(function() {
			content.evalScripts()
		}, 10);
	},

	contentFromAnonymousTable: function() {
		var div = document.createElement('div');
		div.innerHTML = '<table><tbody>' + this.content + '</tbody></table>';
		return $A(div.childNodes[0].childNodes[0].childNodes);
	}
}

var Insertion = new Object();

Insertion.Before = Class.create();
Insertion.Before.prototype = Object.extend(new Abstract.Insertion('beforeBegin'), {
	initializeRange: function() {
		this.range.setStartBefore(this.element);
	},

	insertContent: function(fragments) {
		fragments.each((function(fragment) {
			this.element.parentNode.insertBefore(fragment, this.element);
		}).bind(this));
	}
});

Insertion.Top = Class.create();
Insertion.Top.prototype = Object.extend(new Abstract.Insertion('afterBegin'), {
	initializeRange: function() {
		this.range.selectNodeContents(this.element);
		this.range.collapse(true);
	},

	insertContent: function(fragments) {
		fragments.reverse(false).each((function(fragment) {
			this.element.insertBefore(fragment, this.element.firstChild);
		}).bind(this));
	}
});

Insertion.Bottom = Class.create();
Insertion.Bottom.prototype = Object.extend(new Abstract.Insertion('beforeEnd'), {
	initializeRange: function() {
		this.range.selectNodeContents(this.element);
		this.range.collapse(this.element);
	},

	insertContent: function(fragments) {
		fragments.each((function(fragment) {
			this.element.appendChild(fragment);
		}).bind(this));
	}
});

Insertion.After = Class.create();
Insertion.After.prototype = Object.extend(new Abstract.Insertion('afterEnd'), {
	initializeRange: function() {
		this.range.setStartAfter(this.element);
	},

	insertContent: function(fragments) {
		fragments.each((function(fragment) {
			this.element.parentNode.insertBefore(fragment,
					this.element.nextSibling);
		}).bind(this));
	}
});

/*--------------------------------------------------------------------------*/

Element.ClassNames = Class.create();
Element.ClassNames.prototype = {
	initialize: function(element) {
		this.element = $(element);
	},

	_each: function(iterator) {
		this.element.className.split(/\s+/).select(function(name) {
			return name.length > 0;
		})._each(iterator);
	},

	set: function(className) {
		this.element.className = className;
	},

	add: function(classNameToAdd) {
		if (this.include(classNameToAdd)) return;
		this.set(this.toArray().concat(classNameToAdd).join(' '));
	},

	remove: function(classNameToRemove) {
		if (!this.include(classNameToRemove)) return;
		this.set(this.select(function(className) {
			return className != classNameToRemove;
		}).join(' '));
	},

	toString: function() {
		return this.toArray().join(' ');
	}
}

Object.extend(Element.ClassNames.prototype, Enumerable);
var Selector = Class.create();
Selector.prototype = {
	initialize: function(expression) {
		this.params = {classNames: []};
		this.expression = expression.toString().strip();
		this.parseExpression();
		this.compileMatcher();
	},

	parseExpression: function() {
		function abort(message) {
			throw 'Parse error in selector: ' + message;
		}

		if (this.expression == '')  abort('empty expression');

		var params = this.params, expr = this.expression, match, modifier, clause, rest;
		while (match = expr.match(/^(.*)\[([a-z0-9_:-]+?)(?:([~\|!]?=)(?:"([^"]*)"|([^\]\s]*)))?\]$/i)) {
			params.attributes = params.attributes || [];
			params.attributes.push({name: match[2], operator: match[3], value: match[4] || match[5] || ''});
			expr = match[1];
		}

		if (expr == '*') return this.params.wildcard = true;

		while (match = expr.match(/^([^a-z0-9_-])?([a-z0-9_-]+)(.*)/i)) {
			modifier = match[1],clause = match[2],rest = match[3];
			switch (modifier) {
				case '#':	   params.id = clause; break;
				case '.':	   params.classNames.push(clause); break;
				case '':
				case undefined: params.tagName = clause.toUpperCase(); break;
				default:		abort(expr.inspect());
			}
			expr = rest;
		}

		if (expr.length > 0) abort(expr.inspect());
	},

	buildMatchExpression: function() {
		var params = this.params, conditions = [], clause;

		if (params.wildcard)
			conditions.push('true');
		if (clause = params.id)
			conditions.push('element.id == ' + clause.inspect());
		if (clause = params.tagName)
			conditions.push('element.tagName.toUpperCase() == ' + clause.inspect());
		if ((clause = params.classNames).length > 0)
			for (var i = 0; i < clause.length; i++)
				conditions.push('Element.hasClassName(element, ' + clause[i].inspect() + ')');
		if (clause = params.attributes) {
			clause.each(function(attribute) {
				var value = 'element.getAttribute(' + attribute.name.inspect() + ')';
				var splitValueBy = function(delimiter) {
					return value + ' && ' + value + '.split(' + delimiter.inspect() + ')';
				}

				switch (attribute.operator) {
					case '=':	   conditions.push(value + ' == ' + attribute.value.inspect()); break;
					case '~=':	  conditions.push(splitValueBy(' ') + '.include(' + attribute.value.inspect() + ')'); break;
					case '|=':	  conditions.push(
							splitValueBy('-') + '.first().toUpperCase() == ' + attribute.value.toUpperCase().inspect()
							); break;
					case '!=':	  conditions.push(value + ' != ' + attribute.value.inspect()); break;
					case '':
					case undefined: conditions.push(value + ' != null'); break;
					default:		throw 'Unknown operator ' + attribute.operator + ' in selector';
				}
			});
		}

		return conditions.join(' && ');
	},

	compileMatcher: function() {
		this.match = new Function('element', 'if (!element.tagName) return false; \
		return ' + this.buildMatchExpression());
	},

	findElements: function(scope) {
		var element;

		if (element = $(this.params.id))
			if (this.match(element))
				if (!scope || Element.childOf(element, scope))
					return [element];

		scope = (scope || document).getElementsByTagName(this.params.tagName || '*');

		var results = [];
		for (var i = 0; i < scope.length; i++)
			if (this.match(element = scope[i]))
				results.push(Element.extend(element));

		return results;
	},

	toString: function() {
		return this.expression;
	}
}

Object.extend(Selector, {
	matchElements: function(elements, expression) {
		var selector = new Selector(expression);
		return elements.select(selector.match.bind(selector));
	},

	findElement: function(elements, expression, index) {
		if (typeof expression == 'number') index = expression,expression = false;
		return Selector.matchElements(elements, expression || '*')[index || 0];
	},

	findChildElements: function(element, expressions) {
		return expressions.map(function(expression) {
			return expression.strip().split(/\s+/).inject([null], function(results, expr) {
				var selector = new Selector(expr);
				return results.inject([], function(elements, result) {
					return elements.concat(selector.findElements(result || element));
				});
			});
		}).flatten();
	}
});

function $$() {
	return Selector.findChildElements(document, $A(arguments));
}
var Form = {
	reset: function(form) {
		$(form).reset();
		return form;
	}
};

Form.Methods = {
	serialize: function(form) {
		var elements = Form.getElements($(form));
		var queryComponents = new Array();

		for (var i = 0; i < elements.length; i++) {
			var queryComponent = Form.Element.serialize(elements[i]);
			if (queryComponent)
				queryComponents.push(queryComponent);
		}

		return queryComponents.join('&');
	},

	getElements: function(form) {
		form = $(form);
		var elements = new Array();

		for (var tagName in Form.Element.Serializers) {
			var tagElements = form.getElementsByTagName(tagName);
			for (var j = 0; j < tagElements.length; j++)
				elements.push(tagElements[j]);
		}
		return elements;
	},

	getInputs: function(form, typeName, name) {
		form = $(form);
		var inputs = form.getElementsByTagName('input');

		if (!typeName && !name)
			return inputs;

		var matchingInputs = new Array();
		for (var i = 0; i < inputs.length; i++) {
			var input = inputs[i];
			if ((typeName && input.type != typeName) ||
				(name && input.name != name))
				continue;
			matchingInputs.push(input);
		}

		return matchingInputs;
	},

	disable: function(form) {
		form = $(form);
		var elements = Form.getElements(form);
		for (var i = 0; i < elements.length; i++) {
			var element = elements[i];
			element.blur();
			element.disabled = 'true';
		}
		return form;
	},

	enable: function(form) {
		form = $(form);
		var elements = Form.getElements(form);
		for (var i = 0; i < elements.length; i++) {
			var element = elements[i];
			element.disabled = '';
		}
		return form;
	},

	findFirstElement: function(form) {
		return Form.getElements(form).find(function(element) {
			return element.type != 'hidden' && !element.disabled &&
				   ['input', 'select', 'textarea'].include(element.tagName.toLowerCase());
		});
	},

	focusFirstElement: function(form) {
		form = $(form);
		Field.activate(Form.findFirstElement(form));
		return form;
	}
}

Object.extend(Form, Form.Methods);

/*--------------------------------------------------------------------------*/

Form.Element = {
	focus: function(element) {
		$(element).focus();
		return element;
	},

	select: function(element) {
		$(element).select();
		return element;
	}
}

Form.Element.Methods = {
	serialize: function(element) {
		element = $(element);
		var method = element.tagName.toLowerCase();
		var parameter = Form.Element.Serializers[method](element);

		if (parameter) {
			var key = encodeURIComponent(parameter[0]);
			if (key.length == 0) return;

			if (parameter[1].constructor != Array)
				parameter[1] = [parameter[1]];

			return parameter[1].map(function(value) {
				return key + '=' + encodeURIComponent(value);
			}).join('&');
		}
	},

	getValue: function(element) {
		element = $(element);
		var method = element.tagName.toLowerCase();
		var parameter = Form.Element.Serializers[method](element);

		if (parameter)
			return parameter[1];
	},

	clear: function(element) {
		$(element).value = '';
		return element;
	},

	present: function(element) {
		return $(element).value != '';
	},

	activate: function(element) {
		element = $(element);
		element.focus();
		if (element.select)
			element.select();
		return element;
	},

	disable: function(element) {
		element = $(element);
		element.disabled = '';
		return element;
	},

	enable: function(element) {
		element = $(element);
		element.blur();
		element.disabled = 'true';
		return element;
	}
}

Object.extend(Form.Element, Form.Element.Methods);
var Field = Form.Element;

/*--------------------------------------------------------------------------*/

Form.Element.Serializers = {
	input: function(element) {
		switch (element.type.toLowerCase()) {
			case 'checkbox':
			case 'radio':
				return Form.Element.Serializers.inputSelector(element);
			default:
				return Form.Element.Serializers.textarea(element);
		}
		return false;
	},

	inputSelector: function(element) {
		if (element.checked)
			return [element.name, element.value];
	},

	textarea: function(element) {
		return [element.name, element.value];
	},

	select: function(element) {
		return Form.Element.Serializers[element.type == 'select-one' ?
										'selectOne' : 'selectMany'](element);
	},

	selectOne: function(element) {
		var value = '', opt, index = element.selectedIndex;
		if (index >= 0) {
			opt = element.options[index];
			value = opt.value || opt.text;
		}
		return [element.name, value];
	},

	selectMany: function(element) {
		var value = [];
		for (var i = 0; i < element.length; i++) {
			var opt = element.options[i];
			if (opt.selected)
				value.push(opt.value || opt.text);
		}
		return [element.name, value];
	}
}

/*--------------------------------------------------------------------------*/

var $F = Form.Element.getValue;

/*--------------------------------------------------------------------------*/

Abstract.TimedObserver = function() {
}
Abstract.TimedObserver.prototype = {
	initialize: function(element, frequency, callback) {
		this.frequency = frequency;
		this.element = $(element);
		this.callback = callback;

		this.lastValue = this.getValue();
		this.registerCallback();
	},

	registerCallback: function() {
		setInterval(this.onTimerEvent.bind(this), this.frequency * 1000);
	},

	onTimerEvent: function() {
		var value = this.getValue();
		if (this.lastValue != value) {
			this.callback(this.element, value);
			this.lastValue = value;
		}
	}
}

Form.Element.Observer = Class.create();
Form.Element.Observer.prototype = Object.extend(new Abstract.TimedObserver(), {
	getValue: function() {
		return Form.Element.getValue(this.element);
	}
});

Form.Observer = Class.create();
Form.Observer.prototype = Object.extend(new Abstract.TimedObserver(), {
	getValue: function() {
		return Form.serialize(this.element);
	}
});

/*--------------------------------------------------------------------------*/

Abstract.EventObserver = function() {
}
Abstract.EventObserver.prototype = {
	initialize: function(element, callback) {
		this.element = $(element);
		this.callback = callback;

		this.lastValue = this.getValue();
		if (this.element.tagName.toLowerCase() == 'form')
			this.registerFormCallbacks();
		else
			this.registerCallback(this.element);
	},

	onElementEvent: function() {
		var value = this.getValue();
		if (this.lastValue != value) {
			this.callback(this.element, value);
			this.lastValue = value;
		}
	},

	registerFormCallbacks: function() {
		var elements = Form.getElements(this.element);
		for (var i = 0; i < elements.length; i++)
			this.registerCallback(elements[i]);
	},

	registerCallback: function(element) {
		if (element.type) {
			switch (element.type.toLowerCase()) {
				case 'checkbox':
				case 'radio':
					Event.observe(element, 'click', this.onElementEvent.bind(this));
					break;
				default:
					Event.observe(element, 'change', this.onElementEvent.bind(this));
					break;
			}
		}
	}
}

Form.Element.EventObserver = Class.create();
Form.Element.EventObserver.prototype = Object.extend(new Abstract.EventObserver(), {
	getValue: function() {
		return Form.Element.getValue(this.element);
	}
});

Form.EventObserver = Class.create();
Form.EventObserver.prototype = Object.extend(new Abstract.EventObserver(), {
	getValue: function() {
		return Form.serialize(this.element);
	}
});
if (!window.Event) {
	var Event = new Object();
}

Object.extend(Event, {
	KEY_BACKSPACE: 8,
	KEY_TAB:	   9,
	KEY_RETURN:   13,
	KEY_ESC:	  27,
	KEY_LEFT:	 37,
	KEY_UP:	   38,
	KEY_RIGHT:	39,
	KEY_DOWN:	 40,
	KEY_DELETE:   46,
	KEY_HOME:	 36,
	KEY_END:	  35,
	KEY_PAGEUP:   33,
	KEY_PAGEDOWN: 34,

	element: function(event) {
		return event.target || event.srcElement;
	},

	isLeftClick: function(event) {
		return (((event.which) && (event.which == 1)) ||
				((event.button) && (event.button == 1)));
	},

	pointerX: function(event) {
		return event.pageX || (event.clientX +
							   (document.documentElement.scrollLeft || document.body.scrollLeft));
	},

	pointerY: function(event) {
		return event.pageY || (event.clientY +
							   (document.documentElement.scrollTop || document.body.scrollTop));
	},

	stop: function(event) {
		if (event.preventDefault) {
			event.preventDefault();
			event.stopPropagation();
		} else {
			event.returnValue = false;
			event.cancelBubble = true;
		}
	},

// find the first node with the given tagName, starting from the
// node the event was triggered on; traverses the DOM upwards
	findElement: function(event, tagName) {
		var element = Event.element(event);
		while (element.parentNode && (!element.tagName ||
									  (element.tagName.toUpperCase() != tagName.toUpperCase())))
			element = element.parentNode;
		return element;
	},

	observers: false,

	_observeAndCache: function(element, name, observer, useCapture) {
		if (!this.observers) this.observers = [];
		if (element.addEventListener) {
			this.observers.push([element, name, observer, useCapture]);
			element.addEventListener(name, observer, useCapture);
		} else if (element.attachEvent) {
			this.observers.push([element, name, observer, useCapture]);
			element.attachEvent('on' + name, observer);
		}
	},

	unloadCache: function() {
		if (!Event.observers) return;
		for (var i = 0; i < Event.observers.length; i++) {
			Event.stopObserving.apply(this, Event.observers[i]);
			Event.observers[i][0] = null;
		}
		Event.observers = false;
	},

	observe: function(element, name, observer, useCapture) {
		element = $(element);
		useCapture = useCapture || false;

		if (name == 'keypress' &&
			(navigator.appVersion.match(/Konqueror|Safari|KHTML/)
					|| element.attachEvent))
			name = 'keydown';

		Event._observeAndCache(element, name, observer, useCapture);
	},

	stopObserving: function(element, name, observer, useCapture) {
		element = $(element);
		useCapture = useCapture || false;

		if (name == 'keypress' &&
			(navigator.appVersion.match(/Konqueror|Safari|KHTML/)
					|| element.detachEvent))
			name = 'keydown';

		if (element.removeEventListener) {
			element.removeEventListener(name, observer, useCapture);
		} else if (element.detachEvent) {
			try {
				element.detachEvent('on' + name, observer);
			} catch (e) {
			}
		}
	}
});

/* prevent memory leaks in IE */
if (navigator.appVersion.match(/\bMSIE\b/))
	Event.observe(window, 'unload', Event.unloadCache, false);
var Position = {
// set to true if needed, warning: firefox performance problems
// NOT neeeded for page scrolling, only if draggable contained in
// scrollable elements
	includeScrollOffsets: false,

// must be called before calling withinIncludingScrolloffset, every time the
// page is scrolled
	prepare: function() {
		this.deltaX = window.pageXOffset
				|| document.documentElement.scrollLeft
				|| document.body.scrollLeft
				|| 0;
		this.deltaY = window.pageYOffset
				|| document.documentElement.scrollTop
				|| document.body.scrollTop
				|| 0;
	},

	realOffset: function(element) {
		var valueT = 0, valueL = 0;
		do {
			valueT += element.scrollTop || 0;
			valueL += element.scrollLeft || 0;
			element = element.parentNode;
		} while (element);
		return [valueL, valueT];
	},

	cumulativeOffset: function(element) {
		var valueT = 0, valueL = 0;
		do {
			valueT += element.offsetTop || 0;
			valueL += element.offsetLeft || 0;
			element = element.offsetParent;
		} while (element);
		return [valueL, valueT];
	},

	positionedOffset: function(element) {
		var valueT = 0, valueL = 0;
		do {
			valueT += element.offsetTop || 0;
			valueL += element.offsetLeft || 0;
			element = element.offsetParent;
			if (element) {
				p = Element.getStyle(element, 'position');
				if (p == 'relative' || p == 'absolute') break;
			}
		} while (element);
		return [valueL, valueT];
	},

	offsetParent: function(element) {
		if (element.offsetParent) return element.offsetParent;
		if (element == document.body) return element;

		while ((element = element.parentNode) && element != document.body)
			if (Element.getStyle(element, 'position') != 'static')
				return element;

		return document.body;
	},

// caches x/y coordinate pair to use with overlap
	within: function(element, x, y) {
		if (this.includeScrollOffsets)
			return this.withinIncludingScrolloffsets(element, x, y);
		this.xcomp = x;
		this.ycomp = y;
		this.offset = this.cumulativeOffset(element);

		return (y >= this.offset[1] &&
				y < this.offset[1] + element.offsetHeight &&
				x >= this.offset[0] &&
				x < this.offset[0] + element.offsetWidth);
	},

	withinIncludingScrolloffsets: function(element, x, y) {
		var offsetcache = this.realOffset(element);

		this.xcomp = x + offsetcache[0] - this.deltaX;
		this.ycomp = y + offsetcache[1] - this.deltaY;
		this.offset = this.cumulativeOffset(element);

		return (this.ycomp >= this.offset[1] &&
				this.ycomp < this.offset[1] + element.offsetHeight &&
				this.xcomp >= this.offset[0] &&
				this.xcomp < this.offset[0] + element.offsetWidth);
	},

// within must be called directly before
	overlap: function(mode, element) {
		if (!mode) return 0;
		if (mode == 'vertical')
			return ((this.offset[1] + element.offsetHeight) - this.ycomp) /
				   element.offsetHeight;
		if (mode == 'horizontal')
			return ((this.offset[0] + element.offsetWidth) - this.xcomp) /
				   element.offsetWidth;
	},

	page: function(forElement) {
		var valueT = 0, valueL = 0;

		var element = forElement;
		do {
			valueT += element.offsetTop || 0;
			valueL += element.offsetLeft || 0;

			// Safari fix
			if (element.offsetParent == document.body)
				if (Element.getStyle(element, 'position') == 'absolute') break;

		} while (element = element.offsetParent);

		element = forElement;
		do {
			if (!window.opera || element.tagName == 'BODY') {
				valueT -= element.scrollTop || 0;
				valueL -= element.scrollLeft || 0;
			}
		} while (element = element.parentNode);

		return [valueL, valueT];
	},

	clone: function(source, target) {
		var options = Object.extend({
			setLeft:	true,
			setTop:	 true,
			setWidth:   true,
			setHeight:  true,
			offsetTop:  0,
			offsetLeft: 0
		}, arguments[2] || {})

		// find page position of source
		source = $(source);
		var p = Position.page(source);

		// find coordinate system to use
		target = $(target);
		var delta = [0, 0];
		var parent = null;
		// delta [0,0] will do fine with position: fixed elements,
		// position:absolute needs offsetParent deltas
		if (Element.getStyle(target, 'position') == 'absolute') {
			parent = Position.offsetParent(target);
			delta = Position.page(parent);
		}

		// correct by body offsets (fixes Safari)
		if (parent == document.body) {
			delta[0] -= document.body.offsetLeft;
			delta[1] -= document.body.offsetTop;
		}

		// set position
		if (options.setLeft)   target.style.left = (p[0] - delta[0] + options.offsetLeft) + 'px';
		if (options.setTop)	target.style.top = (p[1] - delta[1] + options.offsetTop) + 'px';
		if (options.setWidth)  target.style.width = source.offsetWidth + 'px';
		if (options.setHeight) target.style.height = source.offsetHeight + 'px';
	},

	absolutize: function(element) {
		element = $(element);
		if (element.style.position == 'absolute') return;
		Position.prepare();

		var offsets = Position.positionedOffset(element);
		var top = offsets[1];
		var left = offsets[0];
		var width = element.clientWidth;
		var height = element.clientHeight;

		element._originalLeft = left - parseFloat(element.style.left || 0);
		element._originalTop = top - parseFloat(element.style.top || 0);
		element._originalWidth = element.style.width;
		element._originalHeight = element.style.height;

		element.style.position = 'absolute';
		element.style.top = top + 'px';
		;
		element.style.left = left + 'px';
		;
		element.style.width = width + 'px';
		;
		element.style.height = height + 'px';
		;
	},

	relativize: function(element) {
		element = $(element);
		if (element.style.position == 'relative') return;
		Position.prepare();

		element.style.position = 'relative';
		var top = parseFloat(element.style.top || 0) - (element._originalTop || 0);
		var left = parseFloat(element.style.left || 0) - (element._originalLeft || 0);

		element.style.top = top + 'px';
		element.style.left = left + 'px';
		element.style.height = element._originalHeight;
		element.style.width = element._originalWidth;
	}
}

// Safari returns margins on body which is incorrect if the child is absolutely
// positioned.  For performance reasons, redefine Position.cumulativeOffset for
// KHTML/WebKit only.
if (/Konqueror|Safari|KHTML/.test(navigator.userAgent)) {
	Position.cumulativeOffset = function(element) {
		var valueT = 0, valueL = 0;
		do {
			valueT += element.offsetTop || 0;
			valueL += element.offsetLeft || 0;
			if (element.offsetParent == document.body)
				if (Element.getStyle(element, 'position') == 'absolute') break;

			element = element.offsetParent;
		} while (element);

		return [valueL, valueT];
	}
}

Element.addMethods();