无间隙图片左右滚动

<div id="demo" style="overflow:hidden;width:1000px;padding:2px;" onmouseover="stopscroll();" onmouseout="doscroll()">
         <div id="demo1" style="white-space:nowrap;padding:0;">
   <img src="ca.gif" height=104 width=172 border=0 />
   <img src="ztdt.gif" height=104 width=172 border=0 />
   <img src="ca.gif" height=104 width=172 border=0 />
   <img src="ca.gif" height=104 width=172 border=0 />
   <img src="ztdt.gif" height=104 width=172 border=0 />
   <img src="ca.gif" height=104 width=172 border=0 />
   <img src="ca.gif" height=104 width=172 border=0 />
   <img src="ztdt.gif" height=104 width=172 border=0 />
   <img src="ca.gif" height=104 width=172 border=0 />
         </div>
</div>
<!--滚动的javascript-->
<script>
var t=demo.scrollWidth
demo1.innerHTML+=demo1.innerHTML
function doMarquee()
{
demo.scrollLeft=demo.scrollLeft<demo.scrollWidth-demo.offsetWidth?demo.scrollLeft+1:t-demo.offsetWidth
}
function doscroll()
{
   sc=setInterval(doMarquee,20)
}
function stopscroll()
{
   clearInterval(sc)
}
doscroll()
</script>