                        課程
                    
                        /前端開發
                        
                            /JavaScript
                        
                        /JS動畫效果

麻煩大家幫忙看看代碼的錯誤！謝謝了

<!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>無標題文檔</title>
</head>
<style?type="text/css">
/*body,div{margin:0?padding:0}*/
#div1{?height:200px;
???????width:200px;
	??background:#F00;
	??filter:alpha(opacity:30);
??????opacity:0.3;
	??
???}
</style>
<script?type="text/javascript">
window.onlond?=?function(){
var?div1=document.getElementById('div1');
?div1.onmouseover=function(){
?	change(100);
?	}
?div1.onmouseout=function(){
	?change(30);
????}
	}	
	var?timer=null;
	var?alpha=30;
	function?change(e){
	var?div1=document.getElementById('div1');
	clearInterval(timer);
			var?speed=0;
	timer=setInterval(function(){
		if(alpha>e){
			speed=-10;
		}
		else{
		????speed=10;	
		}
		if(alpha?==?e){
		clearInterval(timer);
		}
		else{
		alpha+=speed;
		div1.style.filter?='alpha(opacity:'+alpha+')'?;
		div1.style.opacity?=?alpha/100;
		}
	},30)
		
	}
	
</script>
<body>
<div?id="div1"></div>
</body>
</html>