POPDOWNMENUCOUNT=0;
function popDownMenu(linkObj,menuObj){
  this.id=++POPDOWNMENUCOUNT
  this.menuObject=menuObj;
  this.setMenuId(linkObj);
  this.setMenuId(menuObj);
  var instance=this;
  linkObj.onmouseover=function(evt){instance.mouseOver(evt);}; 
  menuObj.style["display"]="none";
}

popDownMenu.prototype.mouseOver=function(evt){
  this.menuObject.style["display"]="";
  var instance=this;
  document.onmouseout=function(evt){instance.mouseOut(evt);}; 
}

popDownMenu.prototype.mouseOut=function(evt){
  evt=new Evt(evt);
  if(evt.source.getAttribute('popdownid')!=this.id){
    this.menuObject.style["display"]="none";
    document.onmouseout=null;
  }
}

popDownMenu.prototype.setMenuId=function(obj){
  obj.setAttribute('popdownid',this.id);
  for(var i=0;i<obj.childNodes.length;i++){
    if(obj.childNodes[i].nodeType==1) this.setMenuId(obj.childNodes[i]);
  }
}