if (document.images) {
        var img0 = new Image(); img0.src = "images/01.gif";
        var img1 = new Image(); img1.src = "images/02.jpg";
        var img2 = new Image(); img2.src = "images/03.jpg";
        var img3 = new Image(); img3.src = "images/04.jpg";
        var img4 = new Image(); img4.src = "images/05.jpg";
        var img5 = new Image(); img5.src = "images/06.jpg";
}

function On(name) {
        if (document.images) {
                document.images['def'].src = eval(name + '.src');
        }
}

function Off() {
        if (document.images) {
                document.images['def'].src = img0.src;
        }
}

function disp_a(url) {
        window.open(url, "a", "width=900,height=600,left=30,top=30,location=1,resizable=1,scrollbars=1,menubar=1,directories=1,status=1,toolbar=1");
}