if (document.images) {
  var defImg = "pack";

  var aboutoff = new Image();
  aboutoff.src = "images/abbrev_menu_01.gif";
  var abouton = new Image();
  abouton.src = "image/abbrev_menuy_01.gif";
  var rulesoff = new Image();
  rulesoff.src = "images/abbrev_menu_02.gif";
  var ruleson = new Image();
  ruleson.src = "images/abbrev_menuy_02.gif";
  var joinoff = new Image();
  joinoff.src = "images/abbrev_menu_03.gif";
  var joinon = new Image();
  joinon.src = "images/abbrev_menuy_03.gif";
  var fansoff = new Image();
  fansoff.src = "images/abbrev_menu_04.jpg";
  var fanson = new Image();
  fanson.src = "images/abbrev_menuy_04.gif";
  var extrasoff = new Image();
  extrasoff.src = "images/abbrev_menu_05.gif";
  var extrason = new Image();
  extrason.src = "images/abbrev_menuy_05.gif";
}

function actMenuItem(imgName) {
  act(imgName);
  inact(defImg);
}

function inactMenuItem(imgName) {
  inact(imgName);
  act(defImg);
}

function act(imgName) {
  if (document.images)
    document.images[imgName].src = eval(imgName + "on.src");
}

function inact(imgName) {
  if (document.images)
    document.images[imgName].src = eval(imgName + "off.src");