Here is a solution that doesn't require Barcoding Software and guarantees info. sharing throughout the process.

* You can create users table that has user login name, password and other
personal info (name, address, Ph. no, email..etc)

* Create a logon form that captures the logon name.

* Create a SQL table that has info by studentID primary key , checkedout
field char(1) (Y/N), checkedon datetime and checkedto char(40). You can
build a view by outer joining this table and the one you already have.
This is recommended only after you choose not to modify the existing SQL
table containing student data

* On the student info. form, you can have 2 methods 'checkin'
and 'checkout'. When a record is checked out, these fields (checkedout,
checkedon and checkedto are written and the record is marked as read only.
It can be checked in by the same user or a user with DBA priveleges.

Hope that works for you.