after their neighbours getting burgled the other day the in-laws have finally listened to my advice and want a bell fitting, only problem is their house has a large conservatory with lots of opening lights and a double door. its not an entry/exit route but it isnt overlooked so its an easy target and needs more than just a door contact......however I dont really want to fit a contact on every single window. What do you learned chaps thin the best (simplest) way to bell it up is ?