I've finished the mission, but I didn't get it completely. One of the things that interest me is why is source different when using the firebug ? Hope I don't give away more than the other already did.

Oh it's a pure spoiler. I think they shouldn't allow this type of help. It did help me, but I don't really feel proud when completing a level like this :P I wonder if I would thought about that. What I noticed is that there is no checkpass method in that javascript which was fishy to me, but I didn'...