// preload website images
if (document.images) {
            preload_image_object = new Image();
            // set image url
            image_url = new Array();
            image_url[0] = "images/background/background.gif";
            image_url[1] = "images/background/background_main.gif";
            image_url[2] = "images/background/background_folds.gif";
            image_url[3] = "images/menu.gif";
            image_url[4] = "images/menuextend.gif";
            image_url[5] = "images/logo.jpg";
            image_url[6] = "images/homepage/quote.jpg";
            image_url[7] = "images/homepage/portfolio.jpg";
            image_url[8] = "images/homepage/printingcom.jpg";
            image_url[9] = "images/homepage/contact.jpg";
            image_url[10] = "images/portfolio/print.jpg";
            image_url[11] = "images/portfolio/design.jpg";
            image_url[12] = "images/portfolio/identity.jpg";
            image_url[13] = "images/portfolio/illustration.jpg";
            image_url[14] = "images/portfolio/close.jpg";
            image_url[15] = "images/portfolio/menufolds/3 roll fold.jpg";
            image_url[16] = "images/portfolio/menufolds/4 roll fold.jpg";
            image_url[17] = "images/portfolio/menufolds/concertina fold.jpg";
            image_url[18] = "images/portfolio/menufolds/cross fold.jpg";
            image_url[19] = "images/portfolio/menufolds/half fold.jpg";
            image_url[20] = "images/portfolio/menufolds/long half fold.jpg";
            image_url[21] = "images/portfolio/menufolds/z fold.jpg";
            

            var i = 0;
            for (i = 0; i <= image_url.length; i++) {
                preload_image_object.src = image_url[i];
            }
        }