JS——取消事件冒泡，实现div的显示与隐藏 event.cancelBubble = true;

<!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>
<style>
    #div1 { width:300px; height:450px; background-color:#99FFFF; display:none;}
</style>

<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
<script>
    window.onload = function(){
        var myBtn1 = document.getElementById("btn1");
        var myDiv1 = document.getElementById("div1");

        myDiv1.onclick = function(ev){
            var divEvent = ev || event;//事件支持火狐浏览器和IE浏览器
            divEvent.cancelBubble = true;//取消事件冒泡
        };
        //点击按钮时，div显示,在函数中加入参数ev
        myBtn1.onclick = function(ev){
            var myEvent = ev || event;//事件支持火狐浏览器和IE浏览器
            myDiv1.style.display = "block";
            myEvent.cancelBubble = true;//取消事件冒泡

        };
        //点击其他的空白页面是，div1消失
        document.onclick = function(){
            myDiv1.style.display = "none";
        };
    };
</script>

</head>

<body>
    <input id="btn1" type="button" value="显示" />
    <div id="div1">点击按钮，我显示了。点击空白处试试</div>
</body>
</html>