Explain this code to me plz

Yo,
I posted a few threads back and I think I might have what Im looking for.
Im not totaly sure how I got it to work but it works.
Could some one explain to me how this code works.
on (rollOver) {
gotoAndPlay(2);
}
Its placed on the tab that activates the menue. On my stage I have 3 frames

  1. the activate tab
  2. for the menue going down
  3. for the menue going up
    I thought that the code would only tell the tab to go to frame 2 and stop. But as you can see it also plays frame 3 when you rollover it again.

Does it work like this
If the time line is on frame 1 then go to frame 2.
But if time line is on frame 2 then frame 2 is 1 and thus go to frame 3 represented as frame 2.
thanks cloak.
http://www.deck-medics.com/DM-2.swf

bump

do you have a fla?

No, Im sorry the file is just shy of the limit; even zipped.
All i want it to do is go to frame 2 with the mouse is over the hit area and frame 3 when the mouse rolls out.
Right now you have to click on the same spot to open and close the menue. I just want it to be smooth. ya know what i mean.

on (rollOver) {
gotoAndStop(“2”);
}

stop being the operative word. this will take the playhead to your mouse down frame. if you want to go to your mouse up frame, you can use this:

on (rollOut) {
gotoAndStop(“3”);
}