/**
 * AJAX Helper
 * Based on Content Loader provided by Dave Crane for "AJAX in Action" book
 *
 * @version 1.1.0
 * @since 1.1.0 - 02 Oct 2007 - Alex Sherman - added support for syncronios call
 * @since 1.0.1 - Denis Weinstein - fixed bug in onReadyState
 * @since 1.0.0 - Original file
 */

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

net.ContentLoader.prototype.loadXMLDoc=function(url,method,params,contentType,sync){
  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,sync);
      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;
 // var httpStatus=req.status;
  if (ready==net.READY_STATE_COMPLETE){
    if (req.status==200 || req.status==0){
      this.onload.call(this);
    }else{
      this.onerror.call(this);
    }
  }
}

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