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(){
        // NOTE: IGNORING ERRORS DON'T HAZZLE THE USER !!!
        /* alert("error fetching data!" 
            +"\n\nreadyState:"+this.req.readyState
            +"\nstatus: "+this.req.status
            +"\nheaders: "+this.req.getAllResponseHeaders()); */
    }
}