var Core = {};

//W3C DOM2 events model
if (document.addEventListener)
{
	Core.addEventListener = function(target, type, listener)
	{
		target.addEventListener(type, listener, false);
	};
	
	Core.removeEventListener = function(target, type, listener)
	{
		target.removeEventListener(type, listener, false);
	};
	
	Core.preventDefault = function(event)
	{
		event.preventDefault();
	};
	
	Core.stopPropagation = function(event)
	{
		event.stopPropagation();
	};
}

//IE Events Model
else if (document.attachEvent)
{
	Core.addEventListener = function(target, type, listener)
	{
		if (Core._findListener(target,type,listener) != -1)
			return;
			
		var listener2 = function()
		{
			var event = window.event;
			
			if (Function.prototype.call)
			{
				listener.call(target,event);
			}
			else
			{
				target._currentListener = listener;
				target._currentListener(event);
				target._currentListener = null;
			}
		};
		
		target.attachEvent("on"+type,listener2);
		
		var listenerRecord =
		{
			target:target,
			type:type,
			listener:listener,
			listener2:listener2
		};
		
		var targetDocument = target.document || target;
		var targetWindow = targetDocument.parentWindow;
		
		var listenerId = "1" + Core._listenerCounter++;
		
		if(!targetWindow._allListeners) targetWindow._allListeners = {};
		targetWindow._allListeners[listenerId] = listenerRecord;
		
		
		if(!target._listeners) target._listeners = [];
		target._listeners[target._listeners.length] = listenerId;
		
		if (!targetWindow._unloadListenerAdded)
		{
			targetWindow._unloadListenerAdded = true;
			targetWindow.attachEvent("onunload", Core._removeAllListeners);
		}
	};
	
	Core.removeEventListener = function(target, type, listener)
	{
		var listenerIndex = Core._findListener(target,type,listener);
		if(listenerIndex == -1) return;
		
		var targetDocument 	= target.document || target;
		var targetWindow	= targetDocument.parentWindow;
		
		var listenerId = target._listeners[listenerIndex];
		var listenerRecord = targetWindow._allListeners[listenerId];
		
		target.detachEvent("on" + type, listenerRecord.listener2);
		target._listeners.splice(listenerIndex, 1);
		
		delete targetWindow._allListeners[listenerId];
	};
	
	Core.preventDefault = function(event)
	{
		event.returnValue = false;
	};
	
	Core.stopPropagation = function(event)
	{
		event.cancelBubble = true;
	};
	
	Core._findListener = function(target,type,listener)
	{
		var listeners = target._listeners;
		if (!listeners) return -1;
		
		var targetDocument 	= target.document || target;
		var targetWindow	= targetDocument.parentWindow;
		
		for (var i = listeners.length - 1; i >= 0; i--)
		{
			var listenerId = listeners[i];
			
			var listenerRecord = targetWindow._allListeners[listenerId];
			
			if (listenerRecord.type == type && listenerRecord.listener == listener)
			{
				return i;
			}
		}
		return -1;

	};
	
	Core._removeAllListeners = function()
	{
		var targetWindow = this;
		for (id in targetWindow._allListeners)
		{
			var listenerRecord = targetWindow._allListeners[id];
			listenerRecord.target.detachEvent("on" + listenerRecord.type, listenerRecord.listener2);
			delete targetWindow._allListeners[id];
		}
	};
	
	Core._listenerCounter = 0;
}

Core.addClass = function(target,theClass)
{
	if(!Core.hasClass(target, theClass))
	{
		if(target.className == "")
		{
			target.className = theClass;
		}
		else
		{
			target.className += " " + theClass;
		}
	}
};

Core.getElementsByClass = function(theClass)
{
	var elementArray = [];
	
	if (document.all)
	{
		elementArray = document.all;
	}
	else
	{
		elementArray = document.getElementsByTagName("*");
	}
	
	var matchedArray 	= [];
	var pattern			= new RegExp("(^| )" + theClass + "( |$)");

	for (var i=0; i < elementArray.length; i++)
	{
		if (pattern.test(elementArray[i].className))
		{
			matchedArray[matchedArray.length] = elementArray[i];		
		}
	}
	
	return matchedArray;
};

Core.hasClass = function(target,theClass)
{
	var pattern	= new RegExp("(^| )" + theClass + "( |$)");
	
	if (pattern.test(target.className))
	{
		return true;
	}
	
	return false;
};


Core.removeClass = function(target,theClass)
{
	var pattern	= new RegExp("(^| )" + theClass + "( |$)");
	
	target.className = target.className.replace(pattern, "$1");
	target.className = target.className.replace(/ $/, "");
};

Core.getComputedStyle = function(element, styleProperty)
{
	var computedStyle= null;
	
	if (typeof element.currentStyle != "undefined")
	{
		computedStyle = element.currentStyle;
	}
	else
	{
		computedStyle = document.defaultView.getComputedStyle(element, null);
	}
	
	return computedStyle[styleProperty];
};

Core.ajaxRequest=function(Url,Method,Data,Handler)
{
	var Request=typeof(XMLHttpRequest)!='undefined'?new XMLHttpRequest():(typeof(window.createRequest)!='undefined'?window.createRequest():false);

	if(!Request)
	{
		try{ Request=new ActiveXObject('Msxml2.XMLHTTP'); } catch(e){ try{ Request=new ActiveXObject('Microsoft.XMLHTTP'); } catch(e){ Request=false; } }
	}
	
	if(Request)
	{
		Request.open(Method,Url,true,false,false);
		Request.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
		Request.onreadystatechange=function(){ try{ Request.readyState==4?(Request.status==200?Handler(Request.responseText):Handler(false)):null; } catch(e){ Handler(false); } };
		Request.send(Data);
	}
};

Core.start = function(runnable)
{
	Core.addEventListener(window, "load" , runnable.init);
};