<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<style>
.on{
background: green;
color:#fff;
}
body div{
background: cornflowerblue;
width: 100px;
height: 100px;
display: none;
alignment-baseline: auto;
}
</style>
</head>
<body>
<input type="button" class="on" value="书籍" />
<input type="button" value="招生" />
<input type="button" value="学校" />
<div style="display: block;" >1111111111</div>
<div>2222222222</div>
<div>3333333333333</div>
</body>
</html>
<script type="text/javascript">
var adiv=document.getElementsByTagName("div")
var abtn=document.getElementsByTagName("input");
for (var i=0;i<abtn.length;i++) {
abtn[i].index=i;
abtn[i].onmouseover=function()
{
for(var i=0;i<abtn.length;i++)
{
abtn[i].className='';
adiv[i].style.display ='none';
}
this.className='on';
adiv[this.index].style.display='block';
}
}
</script>