高分请教xsl+javascript问题

<script>
var xmlHttp = null;
if (window.ActiveXObject) 
{ 
    xmlHttp = new ActiveXObject("Microsoft.XMLHTTP"); 
} 
else if (window.XMLHttpRequest)
{ 
    xmlHttp = new XMLHttpRequest();                
}  if(xmlHttp)
{
    xmlHttp.onreadystatechange=function(){
        if(xmlHttp.readyState==4)
        { 
            if(xmlHttp.status==200)
            {
                var sXml = xmlHttp.responseXml;
                var xslDeclare = sXml.createProcessingInstruction("xml-stylesheet","type='text/xsl' href='我的.xsl'");
                sXml.replaceChild(xslDeclare,sXml.childNodes[1]); //替换原来的xml-stylesheet
                alert(sXml.xml);//output
                
            }
            else
            {
                alert("error happen,error status:"+xmlHttp.status); 
            }
        } 
    }     xmlHttp.open("GET","http://rss.business.sohu.com/rss/gongsixinwen.xml",true); 
    xmlHttp.send(null); }</script>