public static function getCode($val)
    {
        if (self::$_languageFlip === array()) {
            self::$_languageFlip = array_flip(self::$_languages);
        }
        if (array_key_exists($val, self::$_languageFlip)) {
            return strtolower(self::$_languageFlip[$val]);
        }
        return null;
    }