//Ajax XMLHttpRequest wrapper object

var net=new Object();
net.READY_STATE_UNINITIALIZED=0;
net.READY_STATE_LOADING=1;
net.READY_STATE_LOADED=2;
net.READY_STATE_INTERACTIVE=3;
net.READY_STATE_COMPLETE=4;

net.ContentLoader=function(url,onload,onerror){
	this.url=url;
	this.req=null;
	this.onload=onload;
	this.onerror=(onerror) ? onerror : this.defaultError;
	this.loadXMLDoc(url);
}

net.ContentLoader.prototype={
	
	loadXMLDoc:function(url){
		if (window.XMLHttpRequest){
			this.req=new XMLHttpRequest();
		} else if (window.ActiveXObject){
			this.req=new ActiveXObject("Microsoft.XMLHTTP");
		}
		if (this.req){
			try{
				var loader=this;
				this.req.onreadystatechange=function(){
					loader.onReadyState.call(loader);
				}
				this.req.open('GET',url,true);
				this.req.send(null);
			}catch (err){
				this.onerror.call(this);
			}
		}
	},
	
	onReadyState:function(){
		var req=this.req;
		var ready=req.readyState;
		if (ready==net.READY_STATE_COMPLETE){
			var httpStatus=req.status;
			if (httpStatus==200 || httpStatus==0){
				this.onload.call(this);
			}else{
				this.onerror.call(this);
			}
		}
	},
	
	defaultError:function(){
		alert("error fetching data!"
			+"\n\nreadyState:"+this.req.readyState
			+"\nstatus: "+this.req.status
			+"\nheaders: "+this.req.getAllResponseHeaders());
	}
}