activateMenu = function(nav){
  if (document.all && document.getElementById(nav).currentStyle) {  
    var navroot = document.getElementById(nav);
    var lis=navroot.getElementsByTagName("LI");  
    for (i=0; i<lis.length; i++) {
      if(lis[i].lastChild.tagName=="UL"){
        lis[i].onmouseover=function() {	
          this.lastChild.style.display="block";
        }
        lis[i].onmouseout=function() {
          this.lastChild.style.display="none";
        }
      }
    }
  }
}
window.onload= function(){activateMenu('hmenu')}