阻止js冒泡

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>event对象的冒泡</title>
</head>
<style>
#pm2 {
    width:250px;
    height:50px;
    border:2px dashed #CCC;
    padding:10px;
    text-align:center;
    line-height:40px;
    margin:0 auto;
}
#box2 {
    width:250px;
    height:70px;
    background:#000;
    text-align:center;
    margin:0 auto;
    padding:10px;
    padding-top:30px;
}
</style>
<body>
<p id="pm2"></p>
<div id="box2">
  <button id="btn2">点击</button>
</div>
<script>  
    function stopPropagation(e){  
            e = window.event || e;  
            if(document.all){ //document.all只支持IE属性 通过判断浏览器种类  
                e.cancelBubble = true;    
            }  
            else{  
                e.stopPropagation();      
            }  
        }  
            var _pm2 = document.getElementById("pm2");
            var _box2 = document.getElementById("box2");
            var _btn2 = document.getElementById("btn2");  
            _box2.onclick = function (){  
                _pm2.innerHTML = "你点击的是:DIV";  
                alert(1);     
            }  
            _btn2.onclick = function (e){  
                _pm2.innerHTML = "你点击的是：BUTTON";      
                alert(2);
                stopPropagation(e)
            }  
       </script>
</body>
</html>
原文地址：https://www.cnblogs.com/busicu/p/3749229.html