private function getCustomerIP()
    {
        $ip = null;
        if(array_key_exists('X-Forwarded-For', $_SERVER)) {
            $ip = $_SERVER['X-Forwarded-For'];
        } elseif(array_key_exists('HTTP_X_FORWARDED_FOR', $_SERVER)) {
            $ip = $_SERVER['HTTP_X_FORWARDED_FOR'];
        } elseif(array_key_exists('REMOTE_ADDR', $_SERVER)) {
            $ip = $_SERVER['REMOTE_ADDR'];
        }

        return $ip;
    }