MS Access Punch Clock

I need a simple punch clock system developed solely in MS Access with VBA. The concept is to have a single screen with only one entry field. This field the user would enter their code and press enter. The app would then log that user into or out of the db, then reset awaiting the next user. The info would be saved in tables so that total time in could be calculated. This project MUST be done in MS ACCESS 2000 or later. No add-ins or locked code. Also must be done in english, including code behind forms. Max bid should be no more than $30.00