function preloader(){
      var the_images = new Array('../images/nav/home_dn.gif',
      '../images/nav/about_dn.gif.jpg',
      '../images/nav/services_dn.gif',
      '../images/nav/accomplishments_dn.gif',
      '../images/nav/contact_dn.gif',
      '../images/nav/careers_dn.gif');
      preloadImages(the_images);
}

function preloadImages(the_images_array){
    for(var loop = 0; loop < the_images_array.length; loop++){
        var an_image = new Image();
        an_image.src = the_images_array[loop];
    }
}

var theimage;
var theimagesrc;

function swapImage(img,src){

        theimage = img;
        theimagesrc = document.images[img].src;   
        document.images[img].src = src;

}
 
function restoreImage(){
      document.images[theimage].src = theimagesrc;
}