Change Yes / No Field Automatically With Key Management

I am new with Access database and I found almost everything i needed on the internet. There is only one thing I just cant figure out when this looked like one of the easier things. Im making a database where all soorts of keys of all kinds of companies and homes are stored. In this database I want to keep track of the keys that are being used, who has the keys and when the keys are taken and brought back.

Most of these things work except one thing. In the table where I have the keys I have a field wich is 'In use'. This is a yes/no field and I want it to be yes when someone takes a key and to switch back to no when someone returns it. This is possible if it is done by the employees who use the keys but i want it to go automatically so no mistakes are made.

I have one table for the keys, one for the employees that take and return the keys, I use a master with detail form for when someone takes or returns a key and this is all shown in a query.