Problem, please help

Hey, I'm new here, etc, etc.

So, what it is, is that earlier today I was sitting on my computer when I heard the phone ring. Got to go answer it, came back to my computer, and it was turned off. No one else was around so I no one could have turned it off.
My computer is a (old) 2003 HP Pavilion a305w. The main power supply was still on of course, so I simply hit the power button on the case. Nothing happened. So I opened up my tower case, and somehow or other the power button itself came off. Just decided it was time to fall off, I guess. Nothing appeared to be loose, all the cables were in their places, the sound and gfx cards were where they were supposed to be, etc. except for one thing: There are two little bitty cables, black and green, that are twisted around each other. They are connected toether with a clear plastic top. Somehow or other, it fell out of where ever it was supposed to be connected to. I would suppose it has something to do with the power button. My question is, how do I do fix this? I don't have too much experience with computers and nothing like this has ever happened to me before, so don't flame me too hard Thank'ee for your help. Sorry if I wasn't too descriptive, but I'm not too good at that either

 

Welcome aboard. Don't worry, none of us will hurt ya! All the power button does is short two pins out to get it going. Is there a similar connector on the back end of the power switch? Two small pins is all. It just could have gotten loose over the years.