Triggering a movieclip from a timeline

I know this is easy but in all my documentation I can figure out a simple way to play a movieclip when it gets to the end on another one. Basically I want a button to play a movie when it is pressed and at the end of that button movie I want it to play another clip on the main timeline. Also I have a sound in my movieclip waiting to be played on the main timeline and it plays without the clip playing. i guess its because the instance is on the stage but how do I only have it play when its called. Thanks,