Making a Burglar Alarm

My Dad bought me an electronics kit about a year ago. Since then I've been making projects by joining the electronic components together with wire.

My electronics kit looks like this one and I love it because I can make all sorts of projects.
(Click to see a bigger picture)

Recently I used this kit to make a burglar alarm. Firstly I connected all the wires to make a circuit. Next I hooked up the long wire to a door knob so if someone opened the door the wire would pull out of the silver springs you can see in the photo above. When the wire comes out it makes a loud buzzing noise.