Movie Clip Animation Loops on Drop Down Menu

programming flash
1

I have created a drop down menu with an animation taking place within a movie clip called “drop”. Long story short the movie clip loops. I tried putting stop actions in the mc but then my animation doesn’t play. Can anyone tell me what I need to do?

drop._visible=false;

button.onRollOver=function(){
drop._visible=true;

}

button.onRollOut=function(){
drop._visible=false;

}