Hi!
Did you create a huge hollow bloc to containt all your level?
If you did not. ....then create one and apply standard texture.
Insert all your entities,...
compile

secondly : In SED write two action functions: action ()
one for the receiver and one for the transmitter.
Save your work.
Open WED and select the properties for the transmitter.
Under the Behavior tab select the action.
The actions that you coded in SED are now available for your entity.
Let me know if this helps.
Ottawa