Closed door?

[Azmodan45]

I'm wondering how you make a door activated by a switch and remain closed. If you look at Bioshock, for example, the underwater device you take. You're enclosed in on both sides but the front you can, obviously, open and close. Here's what I'm trying to explain:

closed
http://oi54.tinypic.com/2u6fgyd.jpg
and
open
http://oi55.tinypic.com/rw3q4i.jpg

It moves from left to right, right to left. But you don't even have to hold down the button inside. When it closes, it remains closed until something else tells it to open. What device keeps that door locked onto the object but still slides left and right? How can you tell the door to open when you want it to?

Btw, it moves to two different locations and still has the same motion of opening and closing.

[RoharDragontamer]

There are a number of ways to do this, either using pistons or movers. If it stops in more than two positions, it's probably done with multiple movers. If it's only moving from open to close, then its possibly an invisible piston. Attach a piston to an immovable sidewall, and your door. Tweak the piston so its input property is set to direction. Then you need to attach a switch, or logic component to the piston. When a signal is on, the door moves one way, when it's off it moves another.