兼容性写法与事件处理-优快云博客

判断当前对象
火狐谷歌等 event.target.id
ie678 event.srcElement.id
兼容性写法：
var targetId = event.target? event.target.id :event.srcElement.id;

document.body.style.overflow = “hidden”; //不显示滚动条

document.body.style.overflow = “visible”; //显示滚动条

<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
    <style>
        body{
            height: 3000px;
        }
        #mask{
            width: 100%;
            height: 100%;
            opacity: 0.4;
            filter:alpha(opacity=40);
            background-color: #000;
            position: fixed;  /*定位的盒子一定要有宽度*/
            top: 0;
            left: 0;
            display: none;
        }
        #show{
            width: 300px;
            height: 300px;
            background-color: #fff;
            position: fixed;
            top: 50%;
            left: 50%;
            margin:-150px 0 0 -150px;
            display: none;
        }
    </style>
</head>
<body>
<a href="javascript:;" id="login">注册</a>
<a href="javascript:;">登录</a>
<div id="mask"></div>
<div id="show"></div>
</body>
</html>
<script>
    function $(id){return document.getElementById(id)}
    var login = $("login");
    var mask = $("mask");
    var show = $("show");
    login.onclick = function (event) {
        mask.style.display = "block";
        show.style.display = "block";
        document.body.style.overflow = "hidden"; //不显示滚动条
        //取消冒泡
        var event = event || window.event;
        if(event && event.stopPropagation){
            event.stopPropagation();
        }else {
            event.cancelBubble = true;
        }

    }
    document.onclick = function (event) {
        var event = event || window.event;
        var targetId = event.target ? event.target.id : event.srcElement.id; //判断当前对象id
        if(targetId != "show"){
            mask.style.display = "none";
            show.style.display = "none";
            document.body.style.overflow = "visible"; //显示滚动条
        }
    }
</script>