function newImage(arg) {
  if (document.images) {
    rslt = new Image();
    rslt.src = arg;
    return rslt;
  }
}

function changeImages() {
  if (document.images && (preloadFlag == true)) {
    for (var i=0; i<changeImages.arguments.length; i+=2) {
      document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
    }
  }
}

var preloadFlag = false;
function preloadImages() {
  if (document.images) {
    about_over = newImage("/images/about-over.gif");
    characters_over = newImage("/images/characters-over.gif");
    story_over = newImage("/images/story-over.gif");
    gallery_over = newImage("/images/gallery-over.gif");
    links_over = newImage("/images/links-over.gif");
    preloadFlag = true;
  }
}