/*
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){
  this.req=null;
  this.onload=onload;
  this.onerror=(onerror) ? onerror : this.defaultError;
  this.url = url;
  this.loadXMLDoc(url,method,params,contentType);
}

net.ContentLoader.prototype.loadXMLDoc=function(url,method,params,contentType,async){
	
  if (!method){
    method="POST";
  }
  if (!contentType && method=="POST"){
    contentType='application/x-www-form-urlencoded';
  }
  if(!async){
	async = true;  
  }
  if (window.XMLHttpRequest){
    this.req=new XMLHttpRequest();
  } else if (window.ActiveXObject){
		var XmlHttpVersions = new Array("MSXML2.XMLHTTP.6.0",
										 "MSXML2.XMLHTTP.5.0",
										 "MSXML2.XMLHTTP.4.0",
										 "MSXML2.XMLHTTP.3.0",
										 "MSXML2.XMLHTTP",
										 "Microsoft.XMLHTTP");  	
		for(var i=0; i, XmlHttpVersions.length && !this.req; i++){
			try
			{
				this.req=new ActiveXObject(XmlHttpVersions[i]);
			}//end try block
			catch (e){}	//end  catch block	
		}	

  }
  if (this.req){
	 
    try{
      var loader=this;
      this.req.onreadystatechange=function(){
        net.ContentLoader.onReadyState.call(loader);
      }

      if(method == 'POST'){
	  	  
		  this.req.open(method,url,true);

	      if (contentType){
	        this.req.setRequestHeader('Content-Type', contentType);
	      }	 
		  this.req.send(params);
	  }else if(method =='GET'){
		this.req.open(method,url + '?' + escape(params),async);
		this.req.send(null);
	  }
	  
      
    }catch (err){
      this.onerror.call(this);
    }
  }
}


net.ContentLoader.onReadyState=function(){
  var req=this.req;
  var ready=req.readyState;
  
  if (ready==net.READY_STATE_COMPLETE){
  		//alert(req.status);
		//alert(req.statusText);

  	var httpStatus=req.status;

    if (httpStatus==200 || httpStatus==0){
      this.onload.call(this);
    }else{
      this.onerror.call(this);
    }
  }
}

net.ContentLoader.prototype.defaultError=function(){
  	var strValues = "errMsg=error fetching data!"; 
	strValues += "&url="+this.url;
	strValues += "&readyState=" + this.req.readyState;
	strValues += "&status=" + this.req.status;
	strValues += "&headers=" + this.req.getAllResponseHeaders(); 
}