asp.net右键弹出上下文菜单

xtreeView.js
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var ie5=document.all&&document.getElementById
var ns6=document.getElementById&&!document.all
if (ie5||ns6)
var menuobj=document.getElementById("Panel2")
function showmenuie5(e)
{
   
    document.getElementById("url").value = e.srcElement.firstChild.nodeValue;
   
var rightedge=ie5? document.body.clientWidth-event.clientX : window.innerWidth-e.clientX
var bottomedge=ie5? document.body.clientHeight-event.clientY : window.innerHeight-e.clientY
//if the horizontal distance isn't enough to accomodate the width of the context menu
if (rightedge<menuobj.offsetWidth)
//move the horizontal position of the menu to the left by it's width
menuobj.style.left=ie5? document.body.scrollLeft+event.clientX-menuobj.offsetWidth : window.pageXOffset+e.clientX-menuobj.offsetWidth
else
//position the horizontal position of the menu where the mouse was clicked
menuobj.style.left=ie5? document.body.scrollLeft+event.clientX : window.pageXOffset+e.clientX
//same concept with the vertical position
if (bottomedge<menuobj.offsetHeight)
menuobj.style.top=ie5? document.body.scrollTop+event.clientY-menuobj.offsetHeight : window.pageYOffset+e.clientY-menuobj.offsetHeight
else
menuobj.style.top=ie5? document.body.scrollTop+event.clientY : window.pageYOffset+e.clientY
if(ie5)
    window.event.cancelBubble = true;
else if(ns6)
    e.stopPropagation();
menuobj.style.visibility="visible"
   
return false
}
function hidemenuie5(e){
menuobj.style.visibility="hidden"
}
function highlightie5(e){
var firingobj=ie5? event.srcElement : e.target
if (firingobj.className=="menuitems"||ns6&&firingobj.parentNode.className=="menuitems"){
if (ns6&&firingobj.parentNode.className=="menuitems")
firingobj=firingobj.parentNode //up one node
firingobj.style.backgroundColor="highli