function goTop(a, t) {
    a = a || 0.1;
    t = t || 10;

    var x1 = 0;
    var y1 = 0;
    var x2 = 0;
    var y2 = 0;
    var x3 = 0;
    var y3 = 0;

    if (document.documentElement) {
        x1 = document.documentElement.scrollLeft || 0;
        y1 = document.documentElement.scrollTop || 0;
    }
    if (document.body) {
        x2 = document.body.scrollLeft || 0;
        y2 = document.body.scrollTop || 0;
    }
    var x3 = window.scrollX || 0;
    var y3 = window.scrollY || 0;

    var x = Math.max(x1, Math.max(x2, x3));
    var y = Math.max(y1, Math.max(y2, y3));

    var speed = 2 + a;
    window.scrollTo(Math.floor(x / speed), Math.floor(y / speed));
    if (x > 0 || y > 0) {
        var f = "goTop(" + a + ", " + t + ")";
        window.setTimeout(f, t);
    }
}