JS+STRUTS 滚动条问题

小弟用JS+<LOGIC:iterate>弄了个滚动新闻，为什么新闻的标题只能滚动1次？？
如果我把动态的新闻标题改成手写静态的，就正常是好的？
JS的代码是网上找的：<div id="marquees">
<logic:iterate id="tz" name="tzls" indexId="index">
<a href="opernews.do?param=seenews&tiezi_id=${tz.tiezi_id}"
target="main">${index+1}.<font size="3">${tz.tiezi_title}</font>
</a><br><br>
</logic:iterate></div><script language="JavaScript">
with(marquees){
style.width=0;
style.height=marqueesHeight;
style.overflowX="visible";
style.overflowY="hidden";
noWrap=true;
onmouseover=new Function("stopscroll=true");
onmouseout=new Function("stopscroll=false");
}
document.write('<div id="templayer" style="position:absolute;z-index:1;visibility:hidden"></div>');preTop=0; currentTop=0; function init(){
templayer.innerHTML="";
while(templayer.offsetHeight<marqueesHeight){
templayer.innerHTML+=marquees.innerHTML;
}
marquees.innerHTML=templayer.innerHTML+templayer.innerHTML;
window.setInterval("scrollUp()",20);//越大越慢
}
window.document.body.onload=init;function scrollUp(){
if(stopscroll==true) return;
preTop=marquees.scrollTop;
marquees.scrollTop+=1;
if(preTop==marquees.scrollTop){
marquees.scrollTop=templayer.offsetHeight-marqueesHeight;
marquees.scrollTop+=1;}
}
</script>