Thanks Rodalco -- that part I had, though.
Boncuk: This is the direction I was looking for. Two questions though....
1) Door SW1 is opened and the LED lights and buzzer sounds. Door is left open. Door SW2 is opened. Will this circuit still fire the piezo for door SW2?
2) The part I didn't say is that I have 24 rooms to put these indicators on. Each room has four or five doors. So I am talking probably a 100 or more doors. Do you think this method will "scale up" that far? If I needed to, I might be able to join all the doors in a single room so that the LED indicated any door in that particular room, but it would probably be "cooler" if I could sense each of the doors seperately.
What do you think?