JavaScript 兼容新旧版chrome和firefox的桌面通知

1.新/旧版本的chrome和firefox都可支持，IE下不支持因此设置为了在最小化窗口处闪烁显示提示文字。

2.设置为提示窗口显示5秒即关闭。

3.可设置图标和点击提示窗口要跳转到的页面(见输入参数）。

            var timer = null,
                title = $('title').text();  

            $('body').on('click', function() {
                clearInterval(timer);
                $('title').text(title);
            });  

            function showMsgNotification(title, msg , iconUrl ,clickUrl) {
                var Notification = window.Notification || window.mozNotification || window.webkitNotification;
                if (window.webkitNotifications) {
                    //chrome老版本
                    if (window.webkitNotifications.checkPermission() == 0) {
                        var notif = window.webkitNotifications.createNotification(iconUrl, title, msg);
                        notif.display = function() {
                             setTimeout(function() {
                                 notif.close();
                             }, 5000);
                        }
                        notif.onerror = function() {

                        }
                        notif.onclose = function() {

                        }
                        notif.onclick = function() {
                            window.focus();
                            window.location.href = clickUrl;
                        }
                        notif.replaceId = 'Meteoric';
                        notif.show();
                    } else {
                        window.webkitNotifications.requestPermission($jy.notify);
                    }
                }
                else if(Notification) {//支持桌面通知
                    if(Notification.permission == "granted") {//已经允许通知
                        var instance = new Notification(title, {
                            body: msg,
                            icon: iconUrl
                            //renotify : true
                        });  

                        instance.onclick = function() {
                            //$('body').css({'background': 'red'});
                            //console.log('onclick');
                            window.focus();
                            window.location.href = clickUrl;
                            //window.open(clickUrl, "_blank");
                        };
                        instance.onerror = function() {
                            //console.log('onerror');
                        };
                        instance.onshow = function() {
                             setTimeout(function() {
                                 instance.close();
                             }, 5000);
                        };
                        instance.onclose = function() {
                            //console.log('onclose');
                        };
                    }else {//第一次询问或已经禁止通知(如果用户之前已经禁止显示通知，那么浏览器不会再次询问用户的意见，Notification.requestPermission()方法无效)
                        Notification.requestPermission(function(status) {
                            if (status === "granted") {//用户允许
                                var instance = new Notification(title, {
                                    body: msg,
                                    icon: iconUrl
                                });  

                                instance.onclick = function() {
                                    window.focus();
                                    window.location.href = clickUrl;
                                };
                                instance.onerror = function() {
                                    // Something to do
                                };
                                instance.onshow = function() {
                                    // Something to do
                                };
                                instance.onclose = function() {
                                    // Something to do
                                };
                            }else {//用户禁止
                                return false;
                            }
                        });
                    }
                }else {//不支持(IE等)
                    var index = 0;      

                    clearInterval(timer);
                    timer = setInterval(function() {
                        if(index%2) {
                            $('title').text('【　　　】'+ title);//这里是中文全角空格，其他不行
                        }else {
                            $('title').text('【快讯】'+ title);
                        }
                        index++;  

                        if(index > 20) {
                            clearInterval(timer);
                        }
                    }, 500);
                }
            }