The scan works now, I can do things with entities using 'you', the entities don't know it when they are detected though.
I did use enable scan and detect, neither work.
I also tried with my.event = event_scan; with 'event_scan' being a function. But that didn't work.
There is a text in gamestudio command help saying something about 'the wrong way to set entity events'. But that is explained nowere.

Any information on 'the right way to set entity events' is greatly appreciated.