//name  键
                                                                                                                                                                                           //value 值
                                                                                                                                                                                            //expires 过期时间   单位：s

        function setCookie(name, value, expires) {
            if (expires == null) {
                document.cookie = name + "=" + value;
            } else {
                var exDate = new Date();
                exDate = exDate.setTime(exDate.getTime() + 1000 * expires);
                document.cookie = name + "=" + value + ";expires =" + exDate.toUTCString;
            }
        }