var image;
var array;

function preloadImages() {
  if(document.images) {
    array = new Array(9);
    array[0] = 'design/menu-products-hover.gif';
    array[1] = 'design/menu-training-hover.gif';
    array[2] = 'design/menu-contact-hover.gif';
    array[3] = 'design/menu-shop-hover.gif';
    array[4] = 'design/menu-diet-hover.gif';
    array[5] = 'design/side-dvds-hover.gif';
    array[6] = 'design/side-packs-hover.gif';
    array[7] = 'design/side-posters-hover.gif';
    array[8] = 'design/side-gear-hover.gif';
    image = new Array(9);
    for(i = 0; i < array.length; i++) {
      image[i] = new Image();
      image[i].src = array[i];
    }
  }
}

function swapImage(id, url) {
  element = document.getElementById(id);
  if(element) {
    url = "url('" + url + "')";
    element.style.backgroundImage = url;
  }
  return false;
}