by the way, when I put the actionscript in the last keyframes of both of my
layers and choose loop playback, it still loops. Can it not loop no matter what
you choose? I'm an actionscript idiot, so I need some help.

The main timeline is that window that lists your layers. All of those little
squares to the right are frames. Just right-click the last frame in which you
have content, then choose "actions", then type stop(); in the window that
appears. That will keep the whole movie from looping. If you have movieclips
within the movie that are looping, then you have to edit each one separately to
keep them from looping also, as movieclips act independently of the main
timeline.

If you don't understand these terms I'm using, I suggest you run through the
lessons/tutorials that come installed with the software...click on "help", then
choose lessons. They are really helpful.