public function addUser($param)
    {
        if ($this->checkData($param) == 'admin')
        {
            $validate = $this->validator->isValidateRegistration($param);
            if ($validate === true)
            {
                $userName = $this->pdo->quote($param['username']);
                $id_role = $this->pdo->quote($param['id_role']);
                $login = $this->pdo->quote($param['login']);
                $pass = md5(md5(trim($param['pass'])));
                $pass = $this->pdo->quote($pass);
                $email = $this->pdo->quote($param['email']);
                $sql = 'INSERT INTO users (id_role, login, pass, username, email) VALUES ('.$id_role.', '.$login.', '.$pass.', '.$userName.', '.$email.')';
                $result = $this->execQuery($sql);
                if ($result === false)
                {
                    return ERR_LOGIN;
                }
                return $result;
            }
            return $validate;
        }
        return ERR_ACCESS;
    }