if you forgot your code you can reset by undoing the screw on the left which will release the front panel (will open on the opposite side of the screw).
Right in the middle you will find a jumper (black plastic pull up clip to joint two pins together) right next to the black metal bit (heat sink). Just pull it and enter 1234 and yes which should than allow you to enter new code etc (please follow the link of the previous person gave you to download the manual for full instruction on how to programme)
Hope this will help
Rafiq from Edgware
August 2010