I'm working at a office spaceplan. So i've got 2 different colums with the
functions and roomnumber. I would like to get a fault or information message
when there's already a function or department in that room. I can already
make something like it underneath the "data" menu, but everytime I change
something it looks like I do it wrong because I get a message by every change.

can someone help me?

greets