(function(window, jQuery, undefined) {    var HTMLS = {     ovl: '<div class="J_WinpopMask winpop-mask" id="J_WinpopMask"></div>' + '<div class="J_WinpopBox winpop-box" id="J_WinpopBox">' + '<div class="J_WinpopMain winpop-main"></div>' + '<div class="J_WinpopBtns winpop-btns"></div>' + '</div>',     alert: '<input type="button" class="J_AltBtn pop-btn alert-button" value="確定">',     confirm: '<input type="button" class="J_CfmFalse pop-btn confirm-false" value="取消">' + '<input type="button" class="J_CfmTrue pop-btn confirm-true" value="確定">'   }    function Winpop() {     var config = {};     this.get = function(n) {       return config[n];     }      this.set = function(n, v) {       config[n] = v;     }     this.init();   }    Winpop.prototype = {     init: function() {       this.createDom();       this.bindEvent();     },     createDom: function() {       var body = jQuery("body"),         ovl = jQuery("#J_WinpopBox");        if (ovl.length === 0) {         body.append(HTMLS.ovl);       }        this.set("ovl", jQuery("#J_WinpopBox"));       this.set("mask", jQuery("#J_WinpopMask"));     },     bindEvent: function() {       var _this = this,         ovl = _this.get("ovl"),         mask = _this.get("mask");       ovl.on("click", ".J_AltBtn", function(e) {         _this.hide();       });       ovl.on("click", ".J_CfmTrue", function(e) {         var cb = _this.get("confirmBack");         _this.hide();         cb && cb(true);       });       ovl.on("click", ".J_CfmFalse", function(e) {         var cb = _this.get("confirmBack");         _this.hide();         cb && cb(false);       });       mask.on("click", function(e) {         _this.hide();       });       jQuery(document).on("keyup", function(e) {         var kc = e.keyCode,           cb = _this.get("confirmBack");;         if (kc === 27) {           _this.hide();         } else if (kc === 13) {           _this.hide();           if (_this.get("type") === "confirm") {             cb && cb(true);           }         }       });     },     alert: function(str, btnstr) {       var str = typeof str === 'string' ? str : str.toString(),         ovl = this.get("ovl");       this.set("type", "alert");       ovl.find(".J_WinpopMain").html(str);       if (typeof btnstr == "undefined") {         ovl.find(".J_WinpopBtns").html(HTMLS.alert);       } else {         ovl.find(".J_WinpopBtns").html(btnstr);       }       this.show();     },     confirm: function(str, callback) {       var str = typeof str === 'string' ? str : str.toString(),         ovl = this.get("ovl");       this.set("type", "confirm");       ovl.find(".J_WinpopMain").html(str);       ovl.find(".J_WinpopBtns").html(HTMLS.confirm);       this.set("confirmBack", (callback || function() {}));       this.show();     },     show: function() {       this.get("ovl").show();       this.get("mask").show();     },     hide: function() {       var ovl = this.get("ovl");       ovl.find(".J_WinpopMain").html("");       ovl.find(".J_WinpopBtns").html("");       ovl.hide();       this.get("mask").hide();     },     destory: function() {       this.get("ovl").remove();       this.get("mask").remove();       delete window.alert;       delete window.confirm;     }   };    var obj = new Winpop();   window.alert = function(str) {     obj.alert.call(obj, str);   };   window.confirm = function(str, cb) {     obj.confirm.call(obj, str, cb);   }; })(window, jQuery);

 var obj = new Winpop(); // 創建一個Winpop的實例對象 // 覆蓋alert控件 window.alert = function(str) {   obj.alert.call(obj, str); }; // 覆蓋confirm控件 window.confirm = function(str, cb) {   obj.confirm.call(obj, str, cb); };

<script src="http://code.jquery.com/jquery-1.11.1.min.js"></script><script src="winpop.js"></script>