                        課程
                    
                        /前端開發(fā)
                        
                            /JavaScript
                        
                        /JS動(dòng)畫效果

請(qǐng)問大神這哪里錯(cuò)了？為啥沒效果呢？

<!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>無標(biāo)題文檔</title>
<style?type="text/css">
li{
height:100px;
width:200px;
background:red;
margin:10px;
border:#99FF00?4px?solid;
filter:alpha(opacity:30);
opacity:0.3;
}
</style>
</head>
<body>
<script>
window.onload=function(){
var?hello=document.getElementById("hello");
var?world=document.getElementById("world");
//width的變化
/*hello.onmouseover=function(){
???????startmove(this,'width',400);
}
//height的變化
hello.onmouseout=function(){
?????startmove(this,'width',200);
}
*///width的變化
/*world.onmouseover=function(){
???????startmove(this,'height',200);
}
//height的變化
world.onmouseout=function(){
???????startmove(this,'height',100);
}*/
//透明度的變化
world.onmouseover=function(){
???startmove(world,{opacity:100,width:400,height:200});
}
world.onmouseout=function(){
????startmove(world,{opacity:30,width:200,height:100);
?}
}
var?timer=null;
var?flga=true;
function?startmove(obj,json){
clearInterval(obj.timer);
obj.timer=setInterval(function(){
for(var?att?in?json){
var?ic=0;
if(att=='opacity'){
ic=Math.round(parseFloat(getStyle(obj,att))*100);
}else{
?ic=parseInt(getStyle(obj,att));}
var?speed=(json[att]-ic)/8;
speed=speed>0?Math.ceil(speed):Math.floor(speed);
if(ic!=json[att]){
flga=false;
}
if(att=='opacity'){
?obj.style.filter='alpha(opacity:'+ic+')'+speed;
?obj.style.opacity=(ic+speed)/100;
}else{
obj.style[att]=?ic+speed+'px';
?????}
????
??}
??if(flga){
??clearInterval(obj.timer);
??}
},30);
}
function?getStyle(obj,att){
if(obj.currentStyle){
??return?obj.currentStyle[att];
}else{
return?getComputedStyle(obj,false)[att];
}
}
</script>
<ul>
<li?id="hello">
</li>
<li?id="world">
</li>
</ul>
</body>
</html>
請(qǐng)問大神這哪里錯(cuò)了？為啥沒效果呢？