// initialize the menu by preloading images
function initializeImages (menuBackground, otherImages)
  {
    if (document.images)
      {
        var images = ["home", "information", "statement", "gallery", "links", "contact"];
        document.cachedImages = new Array ();
        for (var i = 0; i < images.length; i++)
          {
            var image = new Image ();
            image.src = "png/" + menuBackground + "/menu/" + images[i] + "_on.png";
            document.cachedImages[i] = image;
          }
        if (otherImages)
          {
            for (var i = 0; i < otherImages.length; i++)
              {
                var image = new Image ();
                image.src = otherImages[i];
                document.cachedImages[i] = image;
              }
          }
      }
  }

// swap an image
function swapImage (id, filename)
  {
    var image = getElement (id);
    if (image)
      {
        image.src = filename;
      }
  }

// swap a menu image
function swapMenuImage (menuBackground, imageName, suffix)
  {
    swapImage ("image_menu_" + imageName, "png/" + menuBackground + "/menu/" + imageName + "_" + suffix + ".png");
  }

// get an element
function getElement (id)
  {
    var element;
    if (document.getElementById)
      {
        element = document.getElementById (id);
      }
    if (!element && document.all)
      {
        element = document.all[id];
      }
    if (!element)
      {
        element = document[id];
      }
    return element;
  }