protected function _validateInput()
    {
        $result = true;

        $oxid = $this->getEditObjectId();
        $parameters = \OxidEsales\Eshop\Core\Registry::getConfig()->getRequestParameter("editval");

        // if creating new language, checking if language already exists with
        // entered language abbreviation
        if (($oxid == -1) && $this->_checkLangExists($parameters['abbr'])) {
            $this->addDisplayException('LANGUAGE_ALREADYEXISTS_ERROR');
            $result = false;
        }

        // As the abbreviation is used in database view creation, check for allowed characters
        if (!$this->checkAbbreviationAllowedCharacters($parameters['abbr'])) {
            $this->addDisplayException('LANGUAGE_ABBREVIATION_INVALID_ERROR');
            $result = false;
        }

        // checking if language name is not empty
        if (empty($parameters['desc'])) {
            $this->addDisplayException('LANGUAGE_EMPTYLANGUAGENAME_ERROR');
            $result = false;
        }

        return $result;
    }