Well there are two options. You can create some form of custom security,
meaning that you have a table with usernames and the associated
passwords...then you create a login form which uses a dlookup function to
check the provided values to the values in your table...if they match then
open the rest up...if not then close the application. Of course this sort of
security is not very hard to pass by. The other option would be to use the
build in ULS (user level security). It can be fairly confusing and
complicated so I would strongly suggest you read up on it before trying to
assing it.
Some good references can be found at Conrad's recourse site:
http://home.bendbroadband.com/conradsystems/accessjunkie/resources.html#Security
You would also need to provide the created mdw file (workgroup file) to your
teacher for him to be able to open the mdb file.
HTH
Good luck