js解决IE不支持数组的indexOf()方法

                                if (!Array.indexOf) {
                                    Array.indexOf = function (obj) {
                                        for (var i = 0; i < this.length; i++) {
                                            if (this[i] == obj) {
                                                return i;
                                            }
                                        }
                                        return -1;
                                    }
                                }