大神帮我看一下哪块出错了，非常感谢！！
<!DOCTYPE html>
<html>
<head>
<meta charset="{CHARSET}">
<title>透明度</title>
<style>
body,div{
margin:0;
padding:0;
}
#div1{
width:200px;
height:200px;
background:red;
opacity: 0.3;
filter:alpha(opacity:30);
}
</style>
<script>
window.onload=function(){
var oDiv=document.getElementById('div1');
oDiv.onmouseover=function(){
startMove(100);
}
oDiv.onmouseout=function(){
startMove(30);
}
}
var timer=null;
var alpha=30;
function startMove(iTarget){
var oDiv=document.getElementById('div1');
clearInterval(timer);
timer=setInterval(function(){
var speed=0;
if(alpha<iTarget){
speed=10;
}
else{
speed=-10;
}
if(alpha==iTarget){
clearInterval(timer);
}
else{
alpha=alpha+speed;
oDiv.style.filter='alpha(opacity:'+speed+')';
oDiv.style.opacity=alpha/100;
}
},30);
}
</script>
</head>
<body>
<div id="div1"></div>
</body>
</html>
