Creating a coded door isn't exactly simple, so just look for some coded doors and look at the events. Copy them onto your own bricks and play around with the events, eventually you'll understand. That' what I did.
wich code-door-test save, mine?If not mine, go to this topic: http://forum.blockland.us/index.php?topic=57398.0Download the save and learn from it :D(You need the variables event)