/*
url-loading object and a request queue built on top of it
*/

/* namespacing 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;


/*--- content loader object for cross-browser requests ---*/
net.ContentLoader=function(url,onload,onerror,method,params,contentType){
//alert(params);
	this.req=null;
	this.onload=onload;
	this.onerror=(onerror) ? onerror : this.defaultError;
	this.loadXMLDoc(url,method,params,contentType);
}

net.ContentLoader.prototype.loadXMLDoc=function(url,method,params,contentType){
	if (!method) {
		method="GET";
	}
	if (!contentType && method=="POST") {
		contentType='application/x-www-form-urlencoded';
	}
	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() {
				net.ContentLoader.onReadyState.call(loader);
			}
			this.req.open(method,url,true);
			if (contentType){
				this.req.setRequestHeader('Content-Type', contentType);
			}
			this.req.send(params);
		} catch (err) {
			this.onerror.call(this);
		}
	}
}


net.ContentLoader.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);
		}
	} else {
		this.onload.call(this);
	}
}

net.ContentLoader.prototype.defaultError=function() {
  alert("error fetching data!"
    +"\n\nreadyState:"+this.req.readyState
    +"\nstatus: "+this.req.status
    +"\nheaders: "+this.req.getAllResponseHeaders());
}