Thank you I'll give that a go.

Thanks for the response. OK I'm fine with assigning a pin as an input but how would I change the code to reflect this .thanks.

Hi, New here but stumbled across this.
I am planning on re-using an old wired alarm system that has door and window sensors all over my house terminating under my stairs. Can I combine one sketch into multiple door reed switches on one arduino. That seems to have been asked before but there doesn't seem to be an answer. It would be quite annoying to have 8 arduinos next to each other in order to do so.
Nick