function changeImage(imgName, imgSrc)
{
    document.images[imgName].src = imgSrc;
}


// create an array of the URLs of all images that are to 
// appear in the rollovers

var imgs = new Array("images_nav/navtop_home.jpg","images_nav/currenttop_home.jpg","images_nav/hovertop_home.jpg","images_nav/navtop_bob.jpg","images_nav/currenttop_bob.jpg","images_nav/hovertop_bob.jpg","images_nav/navtop_heroes.jpg","images_nav/currenttop_heroes.jpg","images_nav/hovertop_heroes.jpg","images_nav/navtop_about.jpg","images_nav/currenttop_about.jpg","images_nav/hovertop_about.jpg","images_nav/navtop_partners.jpg","images_nav/currenttop_partners.jpg","images_nav/hovertop_partners.jpg","images_nav/navtop_donations.jpg","images_nav/currenttop_donations.jpg","images_nav/hovertop_donations.jpg","images_nav/navtop_gallery.jpg","images_nav/currenttop_gallery.jpg","images_nav/hovertop_gallery.jpg","images_nav/navtop_contact.jpg","images_nav/currenttop_contact.jpg","images_nav/hovertop_contact.jpg","images_nav/navtop_nominations.jpg","images_nav/currenttop_nominations.jpg","images_nav/hovertop_nominations.jpg");

// create a new empty array

var preload = new Array();

// insert a new Image object into each empty element
// then assign each image URL to the Image objects  

for(var i = 0; i < imgs.length; i++ )
{
  preload[ i ] = new Image();
  preload[ i ].src = imgs[i];
}