.net的滚动字幕问题

我用的Studia2005,在htm里运行可以，但是在aspx里就只能滚动一次，接着就停下了，请高手指点。代码如下：<div id=demoa style="overflow:hidden; width:357px; height:175px;">
<div id=demoa1 >
<a href="#">你可曾有过无数的梦想，</a><br>
<br>
<a href="#">却在时光的流逝里幻灭 </a><br>
<br>
<a href="#">你可曾对未来期待憧憬，</a><br>
<br>
<a href="#">却在成长的岁月中迷失</a><br>
<br>
<a href="#">泰山风景名胜区管理会员会......</a><br>
<br>
            </div>
            <div id=demoa2></div>
                    <script type="text/javascript">
                        var speed1=50
                        demoa2.innerHTML=demoa1.innerHTML
                        function Marquee1(){
                            if(demoa2.offsetTop-demoa.scrollTop<=0)
                                demoa.scrollTop-=demoa1.offsetHeight
                            else{
                                demoa.scrollTop++
                            }
                        }
                        var MyMar1=setInterval(Marquee1,speed1)
                        demoa.onmouseover=function() {clearInterval(MyMar1)}
                        demoa.onmouseout=function() {MyMar1=setInterval(Marquee1,speed1)}
                    </script>
        </div>