How do I not reload a .swf that is already loaded

Question

I have this actionscript attached to a button that loads a
.swf in level 10:
on (release) {
_parent.images.gotoAndStop(1);
loadMovieNum("57Evinrude.swf", 10);
What would I need to add to the above to stop the movie from
reloading the same .swf if it's already loaded and I press the same
button.
Thanks..

Answer 1

Yes, it's a movie clip button, and I've got lots of them.
Each one will load a different .swf file in the same level
replacing each one before it, and I will need to re-enable the
previous movie clip button after clicking a different MC button.
How would I do that? Would I have to give each of the movie clip
buttons an instance name? I know it action script 101, but I'm
lost. This is what I have now. How do I re-enable it when I press
another button, and then I would want that button to become
inactive until another button is press, and so on.
on (rollOver) {
gotoAndPlay(2);
on (rollOut) {
gotoAndPlay(11);
on (release) {
_parent.images.gotoAndStop(4);
loadMovieNum("55Evinrude.swf", 10);
enabled=0
Thanks for your help.