急！！！！关于XML+JS树形目录的问题

这是js代码：
<script>
//code by star 20003-4-7
var HC = "color:red;border:1px solid #cccccc";
var SC = "background-color:#ffffff;border:1px solid #cccccc;color:#000000;";
var IO = null;
function initTree(){
var rootn = document.all.menuXML.documentElement;
var sd = 0;
document.onselectstart = function(){return false;}
document.all.treeBox.appendChild(createTree(rootn,sd));
}
function createTree(thisn,sd){
var nodeObj = document.createElement("span");
var upobj = document.createElement("span");
with(upobj){
style.marginLeft = sd*10;
className = thisn.hasChildNodes()?"hasItems":"Items";
innerHTML = "<img src='images/expand.gif' class=ec>" + thisn.getAttribute("text") +"";

onmousedown = function(){
if(event.button != 1) return;
if(this.getAttribute("cn")){
this.setAttribute("open",!this.getAttribute("open"));
this.cn.style.display = this.getAttribute("open")?"inline":"none";
this.all.tags("img")[0].src = this.getAttribute("open")?"images/expand.gif":"images/contract.gif";
}
if(IO){
IO.runtimeStyle.cssText = "";
IO.setAttribute("selected",false);
}
IO = this;
this.setAttribute("selected",true);
this.runtimeStyle.cssText = SC;
}
onmouseover = function(){
if(this.getAttribute("selected"))return;
this.runtimeStyle.cssText = HC;
}
onmouseout = function(){
if(this.getAttribute("selected"))return;
this.runtimeStyle.cssText = "";
}
oncontextmenu = contextMenuHandle;
onclick = clickHandle;
} if(thisn.getAttribute("treeId") != null){
upobj.setAttribute("treeId",thisn.getAttribute("treeId"));
}
if(thisn.getAttribute("href") != null){
upobj.setAttribute("href",thisn.getAttribute("href"));
}
if(thisn.getAttribute("target") != null){
upobj.setAttribute("target",thisn.getAttribute("target"));
} nodeObj.appendChild(upobj);
nodeObj.insertAdjacentHTML("beforeEnd","<br>") if(thisn.hasChildNodes()){
var i;
var nodes = thisn.childNodes;
var cn = document.createElement("span");
upobj.setAttribute("cn",cn);
if(thisn.getAttribute("open") != null){
upobj.setAttribute("open",(thisn.getAttribute("open")=="true"));
upobj.getAttribute("cn").style.display = upobj.getAttribute("open")?"inline":"none";
if( !upobj.getAttribute("open"))upobj.all.tags("img")[0].src="images/contract.gif";
}

for(i=0;i<nodes.length;cn.appendChild(createTree(nodes[i++],sd+1)));
nodeObj.appendChild(cn);
}
else{
upobj.all.tags("img")[0].src="images/endnode.gif";
}
return nodeObj;
}
window.onload = initTree;
</script><script>
function clickHandle(){
// your code here 
}
function contextMenuHandle(){
event.returnValue = false;
var treeId = this.getAttribute("treeId");
// your code here
}
</script>