insert problem.

Hi,

 I've got this little problem:
I've got two relations:
groups(name text); -- This one contains the name of usergroups;
users (username text, groupid oid, constraint grid primary key(username));
-- The users relation contains the name of the users along with the group
relation's oid as a foreign key.
I'd like to insert a new user and I also know the group's he or she
belongs to:

elmu=> insert into users values('Average Joe', (select oid from groups
where groups.name='grp1'));
ERROR:  parser: parse error at or near "select"

What's wrong with the insertion?

            Thanks in advance

--------------------------------------------------------------------------------
Sebestyén Zoltán AKA Memphisto        It all seems so stupid,
                    it makes me want to give up.
szoli@netvisor.hu            But why should I give up,
                                        when it all seems so stupid?

MAKE INSTALL NOT WAR            And please avoid Necrosoft Widows