var menu_timer;
  function showMenu(menu)
  {
    if(navigator.userAgent.indexOf("Mac_PowerPC") != -1) return;
    if(menu_timer != null) clearTimeout(menu_timer);
    document.getElementById(menu).style['display'] = 'block';
    menu_timer = setTimeout("document.getElementById('" + menu + "').style['display'] = 'none'", 3000);
  }

  function hideMenu(menu)
  {
    if(menu_timer != null) clearTimeout(menu_timer);
    document.getElementById(menu).style['display'] = 'none';
  }