function backToTop() {

    var x1 = x2 = x3 = 0;

    var y1 = y2 = 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;

    }



    x3 = window.scrollX || 0;

    y3 = window.scrollY || 0;



    var x = Math.max(x1, Math.max(x2, x3));

    var y = Math.max(y1, Math.max(y2, y3));



    window.scrollTo(Math.floor(x / 2), Math.floor(y / 2));



    if (x > 0 || y > 0) {

        window.setTimeout("backToTop()", 25);

    }

}