js使用ajax读博客rss示例

<script type="text/javascript">
var xmlHttp;

function createXMLHttpRequest() {
    if (window.ActiveXObject) {
        xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
    } 
    else if (window.XMLHttpRequest) {
        xmlHttp = new XMLHttpRequest();
    }
}

function readRSS(url) {
    createXMLHttpRequest();
    xmlHttp.onreadystatechange = handleStateChange;
    xmlHttp.open("GET", url, true);
    xmlHttp.send(null);

  
}

function handleStateChange() {
    if(xmlHttp.readyState == 4) {
        if(xmlHttp.status == 200) {
            ResultSet();
        }
    }
}

function ResultSet() {
    var results = xmlHttp.responseXML;
    var title = null;
    var item = null;
    var link=null;
    //得到channel
    var ccc=results.getElementsByTagName("channel");
     var headtitle=ccc[0].getElementsByTagName("title")[0].firstChild.nodeValue;
     var headlink=ccc[0].getElementsByTagName("link")[0].firstChild.nodeValue;
     var cell = document.createElement("div");
        cell.innerHTML="<h1><a href="+headlink+" target=_blank>"+headtitle+"</a></h1>
";
        document.getElementById("result").appendChild(cell);
       //得到items
    var items = results.getElementsByTagName("item");
    for(var i = 0; i < items.length; i++) {
        item = items[i];
        link=item.getElementsByTagName("link")[0].firstChild.nodeValue;
        title = item.getElementsByTagName("title")[0].firstChild.nodeValue;
        var cell = document.createElement("div");
        cell.innerHTML="<a href="+link+" target=_blank>"+title+"</a>
";
       document.getElementById("result").appendChild(cell);
    }

}
function readrss1()
{
    var url=document.getElementById("txturl").value;
    if(url=="")
    {
        alert("请输入RSS地址");
        }
    else
        {
            readRSS(url);
            }
    }

</script>
</head>

<body">
  <h1>ajax读rss示例</h1>
  <form >

  <a href="javascript:readRSS('http://www.blogjava.net/rss.aspx')">blogjava原创区 </a>      
   <a href="javascript:readRSS('http://beginner.blogjava.net/rss.aspx')">blogjava新手区 </a>   
    <a href="javascript:readRSS('http://life.blogjava.net/rss.aspx')">blogjava非技术区 </a>   
     <a href="javascript:readRSS('http://general.blogjava.net/rss.aspx')">综合区 </a>

 
     输入一个RSS地址:<input type="text" value="http://www.blogjava.net/wujun/rss.aspx" size=50 id="txturl">
     <input type="button" value="查 看" onclick="readrss1()">

  </form>
    <div id="result"></div>
</body>
</html>