Wiring

[palladin@xxxxxxxxxxx]

I had a window sensor go out in my home security system.  When I pulled
up the magnet from the window sill, the sensor wires pulled out of the
wiring.  I went through the wall to get to the wiring, and boy am I
confused.  I have two, two wire cables coming into the bottom of the
window.  The magnetic sensor has two wires.  Can anyone help me with
the correct way to reconnect the sensor?  The house is wired in zones;
I don't think each individual sensor is wired to the box, in other
words I think each zone is wired in series.  I would appreciate any
help you can give me.  Thanks.