Contao\Input::findPost PHP Method

    public static function findPost($strKey)
    {
        if (isset($_POST[$strKey])) {
            return $_POST[$strKey];
        }
        if (isset($_SESSION['FORM_DATA'][$strKey])) {
            return $strKey == 'FORM_SUBMIT' ? preg_replace('/^auto_/i', '', $_SESSION['FORM_DATA'][$strKey]) : $_SESSION['FORM_DATA'][$strKey];
        }
        return null;
    }