function preload1(u)
{
    var image = new Image();
    image.src = u;
}

function preload_images()
{
    preload1("/static/img/b1.jpg");
    preload1("/static/img/b2.jpg");
    preload1("/static/img/b1r.jpg");
    preload1("/static/img/b2r.jpg");
    preload1("/static/img/b1g.jpg");
    preload1("/static/img/b2g.jpg");
    preload1("/static/img/b1b.jpg");
    preload1("/static/img/b2b.jpg");
}