halem2,
I'm not sure if I really understood what you want, but here's what it seems to me it's happening with you. (Maybe I'm wrong. If so, discard my reply, OK?)
Last year, I created a little DB file with the same login form you've created.
I also had to pass the username value from the login form to other forms and to do this I realized that I couldn't CLOSE the login form after password confirmation.
You said that, after password confirmation, it opens another form and you want to get the username from the login form and put it into a field (combo) in this new form, right? My question for you is: are you closing the login form after password confirmation? If so, it won't work. After password confirmation, you can't close the login form, you have to simply hide it. It will still be opened, but it won't appear on the screen. While it is opened, the other form can get the value from the username field from the login form. But if you close the login form, you lose that link.
Hiding the login form was the way I found to keep the link between its username field and other forms which also have username fields related to each other.
This way, that DLookUp function should work fine.
To hide the login form, use this code after the password confirmation code:
Remember to turn it back to TRUE and also close it when you close the second form or the DB file, for example.
I hope this could help.
Hugs,
Bruce