After Registration

After successful registration I want to update the table cookbook_users fields groupid and active.

I tried:

global $dal;
$tblUsers = $dal->Table('cookbook_users');
$tblUsers->Param["ID"]=$userdata["UserID"];
$tblUsers->Value["groupid"]='member';
$tblUsers->Value["active"]=1;
$tblUsers->Update();

CustomQuery($sql);

Did not work. I think because this only works with data the user added.

Thanks