在IE8中，鼠标移出后，透明度还是100；麻烦大神帮我看看什么问题。
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>透明度动画</title>
<style>
*{padding:0;margin:0}
#div1{width:200px; height:200px; background:red; position:relative; filter:alpha(opacity:30); opacity:0.3;}
</style>
<script>
window.onload=function(){
var oDiv=document.getElementById('div1');
oDiv.onmouseover=function(){
startmove(100);
}
oDiv.onmouseout=function(){
startmove(30);
}
var timer=null,
tmd=30;
function startmove(target){
clearInterval(timer);
timer=setInterval(function(){
var speed=0;
if(tmd>target){
speed=-10;
}else{
speed=10;
}
if(tmd==target){
clearInterval(timer);
}
else{
tmd+=speed;
oDiv.style.opacity=tmd/100;
oDiv.style.filter='alpha(opcity:'+tmd+')';
}
},30)
}
}
</script>
</head>
<body>
<div id="div1">
</div>
</body>
</html>
