activateMenu = function(nav) {
/* currentStyle restricts the Javascript to IE only */
  if (document.all && document.getElementById(nav).currentStyle) {  
  var navroot = document.getElementById(nav);
    /* Get all the list items within the menu */
    var lis=navroot.getElementsByTagName("LI");  
    for (i=0; i<lis.length; i++) {
      /* If the LI has another menu level */
      if(lis[i].lastChild.tagName=="UL"){
        /* assign the function to the LI */
        lis[i].onmouseover=function() {
          /* display the inner menu */
          this.lastChild.style.display="block";
        }
        lis[i].onmouseout=function() {                       
          this.lastChild.style.display="none";
        }
      }
    }
  }
}

window.onload= function(){
    activateMenu('vertnav');  
}