asp中有一段javascipt的网页鼠标滚轮竟然可以一直下滑，底下全是空白，请教
主要代码
<script language="JavaScript">
lastScrollY=0;
function heartBeat(){ 
diffY=document.body.scrollTop; 
percent=.1*(diffY-lastScrollY); 
if(percent>0)percent=Math.ceil(percent); 
else percent=Math.floor(percent); 
document.all.list.style.pixelTop+=percent;
lastScrollY=lastScrollY+percent; 
} 

//打开隐藏视频列表
function openSmall(){
var listmenu=document.getElementById("listmenu");
if(listmenu.style.display=="none"){
listmenu.style.display="block";    
}
else{
listmenu.style.display="none";
}

}
//创建视频播放器div并居中
function openDiv(flvurl){
//var listmenu=document.getElementById('FlvBox');
//listmenu.style.display="block"; 

 var flvDiv=document.createElement("div"); 
 flvDiv.id="FlvBox"; 
 flvDiv.className="flvBoxStyle"; 
 flvDiv.innerHTML="<div id='FlvBox' class='flvBoxStyle'><object classid='clsid:D27CDB6E-AE6D-11cf-96B8-444553540000' codebase='http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=6,0,29,0' width='100%' height='100%'><param name='movie' value='flv/Flvplayer.swf?vcastr_file="+flvurl+"&IsAutoPlay=1' /><param name='quality' value='high' /><param name='allowFullScreen' value='true' /><param name='IsAutoPlay' value='1' /><embed src='flv/Flvplayer.swf?vcastr_file="+flvurl+" &IsAutoPlay=1' width='100%' height='100%' allowfullscreen='true' quality='high' pluginspage='http://www.macromedia.com/go/getflashplayer' type='application/x-shockwave-flash'> </embed></object><a href='#'><img src='images/close_green.png' align='right' onClick='closeDIV() '></a></div>"; 
  document.body.appendChild(flvDiv); 
}
//关闭DIV视频播放器
function closeDIV(){ 
 document.getElementById('FlvBox').parentNode.removeChild(document.getElementById('FlvBox'));  
} 

suspendcode45="<div id=list style='width:204px; height:500px; position:absolute; top:480px;'><div id=listmenu style='display:none'><table border=0 cellpadding=0 cellspacing=0><%for flvi=1 to 20%><tr><td><img src='images/dian_<%=flvi mod 5%>.gif'><a href='#' class='link2' onclick=openDiv('<%=flvRs(1)%>')> <%=flvRs(2)%></td></tr><%flvRs.movenext%><%if flvRs.eof then exit for%><%next%></table></div><div id='Layer1' style='position:absolute; width:204px; height:50px;'><a href='#' onclick=openSmall()><img src='images/111.gif' width='204' height='50' border='0' /></a></div><object classid='clsid:D27CDB6E-AE6D-11cf-96B8-444553540000' codebase='http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=7,0,19,0' width='204' height='50'><param name='movie' value='images/list.swf'><param name='wmode' value='transparent'><param name='quality' value='high'><embed src='images/list.swf' width='205' height='80' quality='high' pluginspage='http://www.macromedia.com/go/getflashplayer' type='application/x-shockwave-flash' wmode='transparent'></embed></object></div>"
document.write(suspendcode45); 
window.setInterval(