$(document).ready(function() {
            if (window.screen && $.browser.version <= 6) {
                $("#menutitle").css("position", "absolute").css({ top: document.documentElement.scrollTop + window.screen.height - 310 });
                var p = window.screen.height - 310;
                window.onscroll = function() {
                    //document.title = document.documentElement.scrollTop + p;
                    $("#menutitle").css({ top: document.documentElement.scrollTop + p, bottom: 0 });
                }
            }
        });
        //<![CDATA[
        var goto_top_type = -1;
        var goto_top_itv = 0;

        function goto_top_timer() {
            var y = goto_top_type == 1 ? document.documentElement.scrollTop : document.body.scrollTop;
            var moveby = 15;

            y -= Math.ceil(y * moveby / 10);//比较慢
            if (y < 0) {
                y = 0;
            }

            if (goto_top_type == 1) {
                document.documentElement.scrollTop = y;
            }
            else {
                document.body.scrollTop = y;
            }

            if (y == 0) {
                clearInterval(goto_top_itv);
                goto_top_itv = 0;
            }
        }

        function goto_top() {
            if (goto_top_itv == 0) {
                if (document.documentElement && document.documentElement.scrollTop) {
                    goto_top_type = 1;
                }
                else if (document.body && document.body.scrollTop) {
                    goto_top_type = 2;
                }
                else {
                    goto_top_type = 0;
                }

                if (goto_top_type > 0) {
                    goto_top_itv = setInterval('goto_top_timer()', 50);
                }
            }
        }
        //]]>