The Activation Lines relay works not just a clue.
Try this:
- Create two actors (actor1, actor2)
- Right click on actor1, New Activation Event
- Select Mouse Button Down event
- Select the button and click on choose actor button
- Click on actor 2 and hit ESC
- Stop the mouse over line to see the tip
When you click on actor1 a activation event will be sent to actor2
Now, you need catch this event on actor2:
- Go to actor contron on actor2
- Add Activation Event
- From actor2
- Destroy Actor(actor1)
Go to game mode and click on actor1: the actor2 will be destroyed.
Activation Event is a powerfull tool. If you choose catch events when "All actors" have sent, you can create a situation that a door only opens when player get all keys!