public static function getForm($url, $token, $field_name)
    {
        $rand = uniqid();

        return '
        <form action="' . $url . '" id="webpay-form-' . $rand . '" method="POST">
            <input type="hidden" name="' . $field_name . '" value="' . $token . '" />
        </form>

        <script>document.getElementById("webpay-form-' . $rand . '").submit();</script>';
    }