I've seen this done where all users details are stored on a table in the following format
UserID FirstName LastName LoginID PasswordID
------ --------- -------- ------- ----------
key inputmask
The user would enter their login details, then in the afterupdate event for the password textbox, VBA would go and check the password given against the username. If the username wasn't recognised, you would be kicked out, if the password wasn't recognised, you would be sent back to the password text box via a 'docmd.gotocontrol' function;
only problem is, I don't know the code to get the blasted thing going myself, but it has been done, therefore you can do it. DO NOT GIVE UP HOPE!! If I find out how to do this, I will put the code in a reply!!!
craig@chyld.co.uk