From the pictures it looks like I used 4 pin relays there. Again, Google is your friend when trying to learn about this stuff ...

http://www.reuk.co.uk/OtherImages/4-...tive-relay.jpg
http://www.reuk.co.uk/OtherImages/5-...tive-relay.jpg

There's a ton of these cheap you can buy off eBay.

Dave.