if(isset($_GET['action']) && ($_GET['action'] == "register")){
    $user = $_POST['name'];
    $uname = mysql_real_escape_string($user);
    $pass = md5($_POST['pass'].'90qdjka*@');
    $upass = mysql_real_escape_string($pass);
    $mailadres = $_POST['mailadres'];
    $umail = mysql_real_escape_string($mailadres);
    $query = "INSERT INTO users (`username`, `password`, `mailadres`, `enabled`, `lastlogin`) VALUES ('".$uname."', '".$upass."', '".$umail."', 1, NOW())";
    if(mysql_query($query)){
        die( 'Registratie was succesvol. Ga naar de <a href="login.php">loginpagina</a>!' );
    }
}