JS读取XML支持火狐

if(navigator.userAgent.indexOf("MSIE")>0)
    {
    orderDoc2 = new ActiveXObject("MSXML2.DOMDocument.3.0"); 
    }
    else
    {
        orderDoc2 = document.implementation.createDocument("","",null); 
    }
 
    
    
     
    orderDoc2.async="false"
    orderDoc2.load("xueli.xml");

var sortField2=orderDoc2.selectNodes("/xueli/xl"); 
function ChooseStateS()
{
     for(var i=0;i<sortField2.length;i++)
     {
       var oOption2 = document.createElement('OPTION'); 
           var prov2=sortField2[i].getAttribute('text'); 
          var provid2=sortField2[i].getAttribute('id'); 
         oOption2.text = " "+prov2+" "; 
         oOption2.value = provid2; 
document.getElementById('xueli').options.add(oOption2); 
     }
}
function xianshi()
{
  document.getElementById("xuanze").style.display="block";
}
function guanbi()
{
  document.getElementById("xuanze").style.display="none";
}

</script>


为什么还是不支持火狐浏览器呢,应该怎么做呢?

补充：.NET技术 ,  ASP.NET