/etc/nologin file -> Is it possible to allow specified users to log in?

From: Tom Brehony (tombrehony.nospam_at_eircom.nospam.net)
Date: 06/30/04 

Date: Wed, 30 Jun 2004 17:01:58 +0100

I need to disable user access to an Aix 4.2 box for the next few days while
I perform
system maintenance. Creating a file called /etc/nologin blocks logins from
all but the
root user.

This is good but ideally I would like for one or two other specified users
to be able to
login as well.

Any ideas on how I can do this?

Tom.