var Ajax = new Object();

Ajax.Request = function(url,id,callbackMethod,callbackParam){
	Page.getPageCenterX();
	Ajax.request = Ajax.createRequestObject();
	Ajax.request.onreadystatechange = callbackMethod;
	Ajax.request.open("POST", url+id, true);
	Ajax.request.send(url);
	Ajax.extra = callbackParam;
}

Ajax.Response = function (){
	if(Ajax.CheckReadyState(Ajax.request)){		
		var response = Ajax.request.responseXML.documentElement;
		var _data = response.getElementsByTagName('category');
		var j;
		for(j=Ajax.extra;j<=4;j++){
			document.getElementById('location_level_'+j).style.display='none';
			document.getElementById('location_level_'+j).length = 0;
		}
		if(_data.length != 0){
			document.getElementById('location_level_'+Ajax.extra).style.display='';
			document.getElementById('location_level_'+Ajax.extra).length = 0;
			document.getElementById('location_level_'+Ajax.extra).options[0] = new Option("All Locations","0");
		}
		var i;
		for (i=0;i<_data.length;i++){
			document.getElementById('location_level_'+Ajax.extra).options[i+1] = new Option(response.getElementsByTagName('data')[i].firstChild.data,response.getElementsByTagName('id')[i].firstChild.data);	
		}
	}
}

Ajax.createRequestObject = function(){
	var obj;
	if(window.XMLHttpRequest){
		obj = new XMLHttpRequest();
	}
	else if(window.ActiveXObject){
		obj = new ActiveXObject("MSXML2.XMLHTTP");
	}
	return obj;
}

Ajax.CheckReadyState = function(obj){
	if(obj.readyState == 4){
		if(obj.status == 200){
			return true;
		}
	}
}

var Page = new Object();
Page.width;
Page.height;
Page.top;

Page.getPageCenterX = function (){
	var fWidth;
	var fHeight;		
	//For old IE browsers 
	if(document.all){ 
		fWidth = document.body.clientWidth; 
		fHeight = document.body.clientHeight; 
	} 
	//For DOM1 browsers 
	else if(document.getElementById &&!document.all){ 
		fWidth = innerWidth; 
		fHeight = innerHeight; 
	} 
	else if(document.getElementById){ 
		fWidth = innerWidth; 
		fHeight = innerHeight; 		
	} 
	//For Opera 
	else if (is.op) { 
		fWidth = innerWidth; 
		fHeight = innerHeight; 		
	} 
	//For old Netscape 
	else if (document.layers) { 
		fWidth = window.innerWidth; 
		fHeight = window.innerHeight; 		
	}
	Page.width = fWidth;
	Page.height = fHeight;
	Page.top = window.document.body.scrollTop;
}