var images_to_preload = [
        "http://www.rockthecampus.org/images/buy_tickets-B.png",
        "http://www.rockthecampus.org/images/btn-prev-hov.png",
        "http://www.rockthecampus.org/images/btn-next-hov.png"
];      


for (i in images_to_preload) {
        var new_image = new Image();
        new_image.src = images_to_preload[i];
}