Koledzy! Napisałem rejestracje w OOP

Wszystko działa, więc proszę o ocenę

Oto kod:
<?php
header("Content-Type: text/html; charset=utf-8"); include("config.php");
class register {
private $nick;
private $pass;
private $email;
private $name;
private $city;
private $age;
private $gg;
public function __construct($nick, $pass, $email, $name, $city, $age, $gg) {
$this->nick=$nick;
$this->email=$email;
$this->imie=$name;
$this->city=$city;
$this->age=$age;
$this->gg=$gg;
}
public function check($nick, $pass, $email, $name) {
$error=false;
if(empty($this->nick)||empty
($this->pass)||empty
($this->email)||empty
($this->name)) { echo "Nie wypełniłeś obowiązkowych pól!<br />"; $error=true; }
}
public function form() {
<form method=post>
Nick: <br />
<input type=text name=nick /><br />
Hasło: <br />
<input type=password name=pass /><br />
E-mail: <br />
<input type=text name=email /><br />
Imię: <br />
<input type=text name=name /><br />
Miejscowość: <br />
<input type=text name=city /><br />
Rok urodzenia: <br />
<input type=text name=age /><br />
Gadu-Gadu: <br />
<input type=text name=gg /><br />
<input type=submit name=submit value=Rejestruj /><br />
";
}
public function addMysql() {
if(isset($_POST['submit'])) { $this->check($_POST['nick'], $_POST['pass'], $_POST['email'], $_POST['name']);
if($error) {
echo "Nie można zarejestrować!<br />"; } else {
$ageresult = $age-$this->age;
$query = "INSERT INTO `users`(`id`, `nick`, `pass`, `email`, `name`, `city`, `age`, `gg`) VALUES ('', '$this->nick', '$this->pass', '$this->email', '$this->name', '$this->city', '$ageresult', '$this->gg');";
@mail('$this->email', 'Rejestracja', 'Witaj $this->nick!\n Dziękujemy za rejestracje na naszej stronie.');
}
} else {
$this->form();
}
}
}
$registered = new register($_POST['nick'], $_POST['pass'], $_POST['email'], $_POST['name'], $_POST['city'], $_POST['age'], $_POST['gg']);
$registered->addMysql();
?>
PS. Wesołych świąt