Gas Pedel Falls Off

This is just one of the many things that has happen with my focus. It all started a couple of weeks ago, I was driving down the free way at about 11:00pm and noticed that my gas pedel wasn't in the right position. I made it home and checked the problem out, it seems that there is a plastic "rod" that is about 2 or 3 inches long that goes through the metel that holds the gas pedel in place. I have fixed this problem about 4 times and it has come out all the times but there doesn't seem to be a pin that is suppose to hold the rod in place. The thing that makes this problem even worse is that sometimes this wants to happen in the middle of trafic or when I need to make a turn to avoid of being hit by an on coming car. Has anyone else had this problem?? Anyways of fixing it???