<html>
<head>
</head>
<body>
<div id="box1" style="">111</div>
<div id="box2" style="display:none">222</div>
<div id="box3" style="display:none">333</div>
<button class="btn1" id="button">按扭</button>
<script type="text/javascript">
var i=0;
document.getElementById('button').onclick=function(){
var a=document.getElementsByTagName('div'),l=a.length;
a[i++].style.display='none';
if(i>=l)i=0;
a[i].style.display='block';
}
</script>
</body>
</html>