function createAjaxObj(){
  var httprequest=false
  if (window.XMLHttpRequest)
  { // if Mozilla, Safari etc
    httprequest=new XMLHttpRequest()
    if (httprequest.overrideMimeType)
      httprequest.overrideMimeType('text/xml')
   }
   else if (window.ActiveXObject)
   { // if IE
     try {
       httprequest=new ActiveXObject("Msxml2.XMLHTTP");
     }
     catch (e){
       try{
          httprequest=new ActiveXObject("Microsoft.XMLHTTP");
       }
       catch (e){}
     }
   }
   return httprequest
}

function RSSReader_ajax(RSS_url, cachetime, divId)
{
  this.RSS_url=RSS_url;
  this.cachetime=cachetime;
  this.tickerid=divId;
  this.title=[];
  this.link=[];
  this.desc=[];
  this.pubdate=[];
  this.ajaxobj=createAjaxObj();
  this.getAjaxcontent();
  document.getElementById(this.tickerid).innerHTML="Initializing....";
}


RSSReader_ajax.prototype.getAjaxcontent=function()
{
  if (this.ajaxobj)
  {
    var instanceOfTicker=this;
    this.ajaxobj.onreadystatechange=function(){instanceOfTicker.initialize();}
    var rssURL="http://rss.sina.com.cn/news/allnews/sports.xml";
    //alert(rssURL);
    //var submitURL="rss?url="+this.RSS_url+"&cache="+this.cachetime;
    this.ajaxobj.open('GET', rssURL, true);
    this.ajaxobj.send(null);
  }
}

RSSReader_ajax.prototype.initialize=function()
{
  if (this.ajaxobj.readyState == 4)
  {
    if (this.ajaxobj.status==200)
    {
      var xmldata=this.ajaxobj.responseXML;
      if(xmldata.getElementsByTagName("item").length==0)
      {
        document.getElementById(this.tickerid).innerHTML="<b>Error</b> fetching remote RSS feed!<br />"+this.ajaxobj.responseText;
        return;
      }
      var instanceOfTicker=this;
      this.feeditems=xmldata.getElementsByTagName("item");
      //alert(this.feeditems.length);
      for (var i=0; i<this.feeditems.length; i++)
      {
        this.title[i]=this.feeditems[i].getElementsByTagName("title")[0].firstChild.nodeValue;
        this.link[i]=this.feeditems[i].getElementsByTagName("link")[0].firstChild.nodeValue;
        //this.desc[i]=this.feeditems[i].getElementsByTagName("desciption")[0].firstChild.nodeValue;
        this.pubdate[i]=this.feeditems[i].getElementsByTagName("pubDate")[0].firstChild.nodeValue;
      }
      //alert(this.title[0]);
      this.rotatemsg();
    }
  }
}
RSSReader_ajax.prototype.rotatemsg=function()
{
  var tickerDiv=document.getElementById(this.tickerid);
  var tickercontent="";
  for( var i=0;i<this.title.length;i++)
  {
    var linktitle='<div class="rsstitle"><a href="'+this.link[i]+'">'+this.title[i]+'</a></div>';
   // var description='<div class="rssdescription">'+this.desc[i]+'</div>';
    var feeddate='<div class="rssdate">'+this.pubdate[i]+'</div>';
    tickercontent=tickercontent+linktitle+feeddate;
  }
  tickerDiv.innerHTML=tickercontent;
}