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

net.ContentLoader.prototype.loadXMLDoc=function(url,method,async,params,contentType){
  if (!method){
    method="POST";
  }
  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,async);
      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;
  if (req.readyState == net.READY_STATE_COMPLETE) {
    if (req.status==200 || req.status==0){
      if (this.onload)
      	this.onload.call(this.object,this);
    }else{
	  if (this.onerror)
      	this.onerror.call(this.object);
    }
  }
}

net.ContentLoader.prototype.defaultError=function(){
	alert("Error al comunicarse con el servidor");
}