var stopscroll = false; 
var scrollElem = document.getElementById("andyscroll"); 
var marqueesHeight = scrollElem.style.height; 
scrollElem.onmouseover = new Function('stopscroll = true'); 
scrollElem.onmouseout = new Function('stopscroll = false'); 
var preTop = 0; 
var currentTop = 0; 
var stoptime = 0; 
var leftElem = document.getElementById("scrollmessage"); 
scrollElem.appendChild(leftElem.cloneNode(true)); 
init_srolltext(); 
function init_srolltext(){ 
scrollElem.scrollTop = 0; 
setInterval('scrollUp()', 20);//的面的这个参数25, 是确定滚动速度的, 数值越小, 速度越快 
} 
function scrollUp(){ 
if(stopscroll) return; 
currentTop += 1; //设为1, 可以实现间歇式的滚动; 设为2, 则是连续滚动 
if(currentTop == 41) { 
stoptime += 1; 
currentTop -= 1; 
if(stoptime == 180) { 
currentTop = 0; 
stoptime = 0; 
} 
}else{ 
preTop = scrollElem.scrollTop; 
scrollElem.scrollTop += 1; 
if(preTop == scrollElem.scrollTop){ 
scrollElem.scrollTop = 0; 
scrollElem.scrollTop += 1; 
} 
} 
}