Code
treeview.js   
  var   menuskin   =   "skin";   
  var   node   =   null;   
    
    
  //Calculate   string   length,   one   chinese   char   impropriate   two   byte.   
  String.prototype.lenB   =   function()   
  {   
  return   this.replace(/[^\x00-\xff]/g,"**").length;   
  }   
    
    
  function   hideMenu()     
  {   
  popupMenu.style.visibility   =   "hidden";   
  }   
    
  function   highlighItem()     
  {   
  if   (event.srcElement.className   ==   "menuitems")     
  {   
  event.srcElement.style.backgroundColor   =   "highlight";   
  event.srcElement.style.color   =   "white";   
  }   
  }   
    
  function   lowlightItem()     
  {   
  if   (event.srcElement.className   ==   "menuitems")     
  {   
  event.srcElement.style.backgroundColor   =   "";   
  event.srcElement.style.color   =   "black";   
  window.status   =   "";   
  }   
  }   
    
  //Call   pop   menu   function   
  function   clickItem()     
  {           
  if   (event.srcElement.className   ==   "menuitems")     
  {   
  if(event.srcElement.getAttribute("func")   ==   "add"   &&   node   !=   null)   
  {   
  var   strNewNodeName;   
  strNewNodeName   =   prompt('请输入新的目录名字:','');   
  if(strNewNodeName.lenB()   <   20   &   strNewNodeName.lenB()   >   0) {   
  window.document.getElementById("TBNewCatalogName").value   =   strNewNodeName;   
  document.all.Button1.click();   
  }   
  else   
  alert("目录名长度不对");   
  }   
  else   if   (event.srcElement.getAttribute("func")   ==   "delete"   &&   node   !=   null)   
  {   
  if(confirm("确定要删除此目录吗?"))     
  {   
  if(window.document.getElementById("TBNodeIndex").value   ==   "0")   
  alert("不能删除此目录.");   
  else   
  document.all.Button2.click();   
  }   
  }   
  else   if   (event.srcElement.getAttribute("func")   ==   "modify"   &&   node   !=   null)   
  {   
  //User   can't   edit   root   node   name   
  if(window.document.getElementById("TBNodeIndex").value   !=   "0")   
  {   
  var   strEditNodeName;   
  strEditNodeName   =   prompt('请输入新的目录名字:','');   
  if(strEditNodeName.lenB()   <   20   &   strEditNodeName.lenB()   >   0) {   
  window.document.getElementById("TBNewCatalogName").value   =   strEditNodeName;   
  document.all.Button3.click();   
  }   
  else   
  alert("目录名长度不对");   
  }   
  else   
  alert("不能修改根结点");   
  }   
  }   
  }   
        
          
  function   TreeView1.oncontextmenu()   
  {   
  var   nodeindex   =   event.treeNodeIndex;   
  if   (typeof(nodeindex)   ==   "undefined")   
  {   
  node   =   null;   
  return;   
  }   
            
  node   =   TreeView1.getTreeNode(nodeindex);   
  window.document.getElementById("TBNodeIndex").value   =   nodeindex;   
            
    
  var   rightedge   =   document.body.clientWidth-event.clientX;   
  var   bottomedge   =   document.body.clientHeight-event.clientY;   
  if   (rightedge   <popupMenu.offsetWidth)   
  {   
  //old   author   code   
  //popupMenu.style.left   =   document.body.scrollLeft   +   event.clientX   -   popupMenu.offsetWidth;   
  popupMenu.style.left   =   30;   
  }   
  else   
  {   
  //old   author   code   
  //popupMenu.style.left   =   document.body.scrollLeft   +   event.clientX;   
  popupMenu.style.left   =   30;   
  }   
  if   (bottomedge   <popupMenu.offsetHeight)   
  {   
  popupMenu.style.top   =   document.body.scrollTop   +   event.clientY   -   popupMenu.offsetHeight;   
  }   
  else   
  {   
  popupMenu.style.top   =   document.body.scrollTop   +   event.clientY;   
  }   
  popupMenu.style.visibility   =   "visible";   
  return   false;   
  }