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,method,params,contentType){	
  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.toLowerCase()=="post"){
    contentType='application/x-www-form-urlencoded;';
  }
  if(method.toLowerCase()=="get"&&params!=null&&params!="")
  {
	  url+="?"+encodeURI(params);
	  params=null;
  }  
  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.setRequestHeader("Cache-Control","no-cache"); 
      }
      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);
    }
  }
}

net.ContentLoader.prototype.defaultError=function(){
	window.status="²Ù×÷ʧ°Ü";
/*  alert("error fetching data!"
    +"\n\nreadyState:"+this.req.readyState
    +"\nstatus: "+this.req.status
    +"\nheaders: "+this.req.getAllResponseHeaders());*/
}