$(function () {

var demo = $("#demo")[0];

var demo1 = $("#demo1")[0];

var demo2 = $("#demo2")[0];

var speed = 10; //滚动速度值，值越大速度越慢

var nnn = 200 / demo1.offsetHeight;

for (i = 0; i < nnn; i++) {

demo1.innerHTML += "
" + demo1.innerHTML

}

demo2.innerHTML = demo1.innerHTML //克隆demo2为demo1

function Marquee() {

if (demo2.offsetTop - demo.scrollTop <= 0) //当滚动至demo1与demo2交界时

demo.scrollTop -= demo1.offsetHeight //demo跳到最顶端

else {

demo.scrollTop++

}

}

var MyMar = setInterval(Marquee, speed); //设置定时器

demo.onmouseover = function () {

clearInterval(MyMar)

} //鼠标经过时清除定时器达到滚动停止的目的

demo.onmouseout = function () {

MyMar = setInterval(Marquee, speed)

} //鼠标移开时重设定时器

});