Without implementing the Access security (about which I know nothing) you could filter forms based on the results of a login form. Create a Users table that stores names and passwords. ON the button that you want to open the form, call the login as a dialog form. Once the user has entered a correct username and password, then open the form you want.
If you based the salesman's form on a query and you passed the employee identification to the query from the login form, the form would only have sales info pertaining to the logged in salesman.
You would need to ensure that there are no other ways for the salespeople to look at that information - Database Window, other forms ...
HTH
Chris
