Big code door, with built in security.

Have you ever gotten tired of people flipping your switches over and over again, with seemingly no end in the near future? Your solution has arrived! Simply place this at the bottom of a stairwell, input the proper code, pull the lever labeled ENTER, and the doors open. If the code is wrong and the lever is pulled, the floor will disappear and drop the victim into a pool of lava, where he/she will be crushed and burned to death. Its complex enough that XRAYers without extreme experience with redstone wont find out the code, but also easy enough to build in a matter of minutes. Its at the bottom of stairs so that the victim has a greater chance of standing on the trap. This can be altered, but wont be NEARLY as effective (I've done experiments on my server with it. ;3) Changing the code is as simple as placing a redstone torch on top of the levers to be flipped downwards, and redstone on top of all others.
(NOTE: The trap will only be activate if the ENTER lever is pulled with a WRONG code, as to not scare away the victim.)