function ShowMenu(menuName) {
     AbortHide();
     
     var menuID = menuName+'Menu';
     var submenuID = menuName+'SubMenu';
     var menu = document.getElementById(menuID);
     var submenu = document.getElementById(submenuID);
     
     HideAllMenus();
     
     for (var i=0; i<Menus.length; i++) {
       if (Menus[i] == menuID) {
         menu.src = MenuImages[ i*2 + 1];
         break;
       }
     }
     
     if (submenu) {
       ShowElementById('GrayBar');
       ShowElement(submenu);
     }
   }
   
   function AbortHide() {
     if (ScheduledTimeout) {
       clearTimeout(ScheduledTimeout);
     }
     ScheduledTimeout = null;
   }
   
   function ShowElement(el) {
     el.style.visibility='visible';
   }
   
   function ShowElementById(elid) {
     var el = document.getElementById(elid);
     el.style.visibility='visible';
   }
   
   function HideElement(el) {
     el.style.visibility='hidden';
   }
   
   function HideElementById(elid) {
     var el = document.getElementById(elid);
     el.style.visibility='hidden';
   }
   
   function ScheduleHide() {
     AbortHide();
     ScheduledTimeout = setTimeout("ResetMenus()", 400)
   }
   
   function ResetMenus() {
     if (DefaultMenu) {
       ShowMenu(DefaultMenu);
     } else {
       HideAllMenus();
     }
   }
   
   function HideAllMenus() {
     for (var i=0; i < Menus.length; i++) {
       var e = document.getElementById( Menus[i] );
       e.src = MenuImages[ i*2 ];
     }
     
     for (var i=0; i< SubMenus.length; i++) {
       HideElementById( SubMenus[i] );
     }
   }