【急求】：◆难◆文字水平左右滚动特效，且由客户端控制！！！！！！

<body>
<script>
var a,b
</script>
<span style="cursor:hand" onmouseover="a=setInterval('d.scrollLeft--',2)" onmouseout="clearInterval(a)">←</span> 
<div id=d style="width:100;height:20;overflow:hidden">1234567890000000000987654321</div>
<span style="cursor:hand" onmouseover="b=setInterval('d.scrollLeft++',2)" onmouseout="clearInterval(b)">→</span> 
</body>