Sorry to totally derail this thread, but I have to relay this odd story. I worked in GE traffic control division we had a pneumatic press that crimped two wires on to a lamp socket. Pretty straight forward operation. A monkey could be trained to do this job. Fit the socket in, add a black wire and a white wire and hit the mushroom button on the front of the machine. The press would start, the ram would come down, the wires were crimped on and the ram moved back up automatically when it was done. Then one day someone decided it would be a good idea to have their hand in there while their other hand pressed the button. Needless to say, they crimped their fingers. Ouch! The engineer came up with a solution. Let there be two mushroom buttons, one the each side of the press. Now the operator would have to use both hands simultaneously to press the buttons in order to start the cycle. It seemed to be a great solution as you cannot have either hand in the machine while they are both busy pressing the mushroom buttons on the front. Right? A month later someone got their fingers jammed in the press again! WTF? We investigated and found the operator was sitting in a "captain" style chair. The fronts of the arm rests of that particular chair were perfectly in line with the two buttons! When they leaned forward in the chair it activated the press. I guess it's like putting an infinite number of monkeys in a room with typewriters. Eventually one of them will write War and Peace.