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

  var homeoff = new Image();
  homeoff.src = "images/homeoff.png";
  var homeon = new Image();
  homeon.src = "images/homeon.png";
  var aboutoff = new Image();
  aboutoff.src = "images/aboutoff.png";
  var abouton = new Image();
  abouton.src = "images/abouton.png";
  var pastoff = new Image();
  pastoff.src = "images/pastoff.png";
  var paston = new Image();
  paston.src = "images/paston.png";
  var futureoff = new Image();
  futureoff.src = "images/futureoff.png";
  var futureon = new Image();
  futureon.src = "images/futureon.png";
  var galleryoff = new Image();
  galleryoff.src = "images/photooff.png";
  var galleryon = new Image();
  galleryon.src = "images/photoon.png";
  var eventoff = new Image();
  eventoff.src = "images/eventoff.png";
  var eventon = new Image();
  eventon.src = "images/eventon.png";
  var contactoff = new Image();
  contactoff.src = "images/contactoff.png";
  var contacton = new Image();
  contacton.src = "images/contacton.png";
  var thanksoff = new Image();
  thanksoff.src = "images/thanksoff.png";
  var thankson = new Image();
  thankson.src = "images/thankson.png";
}

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");
}