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)
  {
    home_over = newImage("images/home-over.gif");
    about_over = newImage("images/about-over.gif");
    products_over = newImage("images/products-over.gif");
    request_over = newImage("images/request-over.gif");
    support_over = newImage("images/support-over.gif");
    preloadFlag = true;
  }
}