<!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=utf-8" />
<script src="jquery-1.8.1.js"></script>
<title>无标题文档</title>
</head>
<style>
.d3{
width:60px;
height:60px;
border:1px solid red;
}
.d2{
width:40px;
height:40px;
border:1px solid red;
}
.d1{
width:20px;
height:20px;
border:1px solid red;
}
</style>
<body>
<div class="d3">
<div class="d2">
<div class="d1"></div>
</div>
</div>
<form action="test.html">
用户名：<input type="text" id="username"/><br/>
<input type="submit" value="提交" id="sub"/>
</form>
<div id="msg"></div>
</body>
<script type="text/javascript">
$(".d1").bind("click",function(event){//event时间对象 当点击元素时 事件对象被创建 事件处理函数执行完后 事件对象被销毁
$(this).css("background","yellow");
event.stopPropagation();//停止事件冒泡 或者return false;
})
$(".d2").bind("click",function(event){
$(this).css("background","pink")
event.stopPropagation();
})
$(".d3").bind("click",function(event){
$(this).css("background","#000")
event.stopPropagation();
})
</script>
<script type="text/javascript">
$(function(){
$("#sub").bind("click",function(event){
var username=$("#username").val();
if(username==""){
$("#msg").html("<p>文本框的值不能为空</p>");
event.preventDefault();//阻止默认行为 或者用return false;
}
})
})
</script>
</html>