lastScrollY=0; 
function heartBeat(){  
var diffY; 
if (document.documentElement && document.documentElement.scrollTop) 
    diffY = document.documentElement.scrollTop; 
else if (document.body) 
    diffY = document.body.scrollTop 
else 
    {/*Netscape stuff*/} 
     
//alert(diffY); 
percent=.1*(diffY-lastScrollY);  
if(percent>0)percent=Math.ceil(percent);  
else percent=Math.floor(percent);  
document.getElementById("qq_online").style.top=parseInt(document.getElementById("qq_online").style.top)+percent+"px";

lastScrollY=lastScrollY+percent;  
//alert(lastScrollY); 
}
window.setInterval("heartBeat()",1);