function $(id) {
        return document.getElementById(id)
    }
    //向上滚动函数，demo包含demo1与demo2,speed是滚动速度，flag一个网页内有多个时设置为不同的任意字符。
    //by 柳永法(yongfa365)'Blog　www.yongfa365.com
    function totop(demo, demo1, demo2, speed, flag) {
        demo = $(demo);
        demo1 = $(demo1);
        demo2 = $(demo2)
        demo2.innerHTML = demo1.innerHTML
        function Marquee() {
            if (demo2.offsetTop - demo.scrollTop <= 0) {
                demo.scrollTop -= demo1.offsetHeight
            } else {
                demo.scrollTop++
            }
        }
        flag = setInterval(Marquee, speed)
        demo.onmouseover = function() {
            clearInterval(flag);
        }
        demo.onmouseout = function() {
            flag = setInterval(Marquee, speed);
        }
    }