<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
*{margin: 0;padding: 0;}
#div1{
width:200px;
height: 200px;
background-color:red;
margin: 40px auto;
opacity:0.3;
filter:alpha(opacity:30);
cursor: pointer;
}
</style>
<script>
window.onload = function(){
var oDiv=document.getElementById('#div1');
oDiv.onmouseover=function(){
startMove(100);
};
oDiv.onmouseout=function(){
startMove(30);
}
};
var timer=null;
var apa=30;
function startMove(iTarget){
var oDiv=document.getElementById("#div1");
clearInterval(timer);
timer=setInterval(function(){
var speed=0;
if(apa>iTarget){
speed=-10;
}
else{
speed=10;
}
if(apa==iTarget){
clearInterval(timer)
}
else{
apa+=speed;
oDiv.style.filter="alpha(opacity:"+apa+")";
oDiv.style.opacity=apa/100;
}
},30)
}
var oDiv=document.getElementById('#div1'); 不需要#号吧