Validating a User in NT4

I am trying to validate a users ID and Password, this will be used within an Access Database. When it works the database will be on a single domain with over 2500 users.

I want to allow anyone entry to the database and to create, amend or delete records, but only allow them to save the said record if they are who they say they are (thus the reason for validation). I just want it to check the password not send it back so it could be cracked.

I have managed to get the UserID to be placed automatically in a text box when any of the database forms are opened (these text boxes are locked so the user cannot amend them). So I intend to use the details from the text box to be passed along with the entered password. (using an input box)

I have read article Q180548 but can’t get it to work.
I created an System account named Test allow it to used as part of the system and gave it admin rights but still no joy.

If any one could help I would be most grateful.

I have only just taken up VB6 and am not in anyway classed as a programmer although I have created a lot of the database using this program (mostly through trial and loads of errors)

I am using a single server and workstation to trial this database.

Thank you for any help given