[Samba] ask for NT group name

[CHEUNG Chi Wai, Chris]

Dear all,

I have setup a samba 2.2.3a to join NT domain.
It is successful to let specific user access the samba
But once I set a group to access, save domain admin 
to access the samba. It is not done.
I have set in the smb.conf 
valid user = @domain admin, user1
The samba can recongize it is a group call
domain, not domain admin.
How can I set the group name with space bar?

Chris Cheung