$userCheckerAndInserterObj = new UserCheckerAndInserter($this->dbObj, $user_exists, $username, $_POST['pw'], $gender, $this->lang);

$userCheckerAndInserterObj = new UserCheckerAndInserter($this->dbObj, $user_exists, $username, $_POST['pw'],preg_replace("/[^a-z]/i", "n", $gender), $this->lang);