I'm still quite a noob at Hammer, but I'm starting to get the hang of things.
I've followed the Wiki exactly as far as I know, but after hours of frustration, the button just refuses to work! (there's no filters for the box right now, but it did not work with filters either)
The best I've gotten the button to work was that the button gets pushed down, but does not rise again, and the doors closes after about 10 seconds. Usually, the doors is open in about half a second, but totally stops working afterwards.
And another quite irritation problem is that somehow I have created an invisible (even in Hammer) companion cube sized object placed right above the button, which only stops other objects than the player (like a cube or camera)
I must have done quite a load of general wrongness...
Mounds of gratitude to anyone who would be so kind as to check out my .rar file and explain what I have done wrong, so I can continue on with Hammering and in the end, hopefully create something 

