                        课程
                    
                        /前端开发
                        
                            /JavaScript
                        
                        /JS动画效果

为什么我的没有结果

<!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=gb2312" />
<title>无标题文档</title>
<head>
<style type="text/css">
   #div1{
       width:200px;
       height:200px;
       background:red;
       filter:alpha(opacity:30);
       opacity:0.3;
   }
</style>
<script type="text/javascript">
   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+=speed;
           oDiv.style.filter='alpha(opactiy:'+alpha+')';
           oDiv.style.opactiy=alpha/100;
       }
       },30)
   }
</script>
</head>

<body>
<div id="div1">

</div>
</body>
</html>