lastScrollY = 0;
    function heartBeat(){
    var diffY;
    if (document.documentElement && document.documentElement.scrollTop)
     diffY = document.documentElement.scrollTop;
    else if (document.body)
     diffY = document.body.scrollTop

    percent=0.1*(diffY-lastScrollY);
    if(percent>0)percent=Math.ceil(percent);
    else percent=Math.floor(percent);
    //document.getElementById("floatQQ").style.top = parseInt(document.getElementById("floatQQ").style.top)+percent+"px";
    document.getElementById("floatQQ").style.top = parseInt(document.getElementById("floatQQ").style.top)+percent+"px";

    lastScrollY=lastScrollY+percent;

    //window.status = diffY+":"+lastScrollY+":"+percent;
    //alert(lastScrollY);
    }

    //下面这段删除后，对联将不跟随屏幕而移动。
    window.setInterval("heartBeat()",1);