// JavaScript Document
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) {
  book_over = newImage("images/book-over.gif");
  articles_over = newImage("images/articles-over.gif");
  resources_over = newImage("images/resources-over.gif");
  about_over = newImage("images/about-over.gif");
  contact_over = newImage("images/contact-over.gif");
  home_over = newImage("images/home-over.gif");
  preloadFlag = true;
 }
}