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);
                }
            }