<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="keywords" content=""/>
<meta name="description" content=""/>
<script src="http://libs.baidu.com/jquery/1.9.0/jquery.js">
</script>
<title></title>
<style>
.id1{ 50px;height: 50px;background: red;}//id1的css样式
</style>
</head>
<body>
<div class="id1" id="num">9</div>
<script type="text/javascript">
var i=9; //创建一个名为i的对象
btn = document.getElementById('num');
btn.onclick=function (){//给id1新建一个点击事件
i=i+1; //每次点击i+1
btn.innerHTML=i;
}
</script>
</body>
</html>