var platform = navigator.platform.substr(0,3);
  var browser = navigator.appName;
  var version = navigator.appVersion.substr(0,1);

  var over = 'false';
  var lastMenu = ' ';
  var styleSheetElement;
  var oldElement;

  function menuOn ( currentMenu ) {
    over = 'true';
    if (lastMenu != ' '){
      hideLastMenu();
    }
    document.images[currentMenu].src = ('/images/'+currentMenu+'_on.gif');
    lastMenu = currentMenu;
  }
  function overChecker ( currentMenu ) {
    over = 'false';
    lastMenu = currentMenu;
    setTimeout("menuOff()", 300);
  }
  function menuOff() {
    if ( over == 'false' ) {
      hideLastMenu();
    }
  }
  function hideLastMenu () {
    document.images[lastMenu].src = '/images/'+lastMenu+'.gif';
  }