Playing a sound on entering a frame/label

I’ve got a file with say 5 sections, each section with a frame label. When I enter a section, I want to play a sound. It should happen when the movie hits that frame label/frame. I’ve tried this:

 
onEnterFrame = function () {
 snd = new Sound(this);
 snd.attachSound("space");
 snd.start(0, 1);
};

It works in that the sound plays, but then it goes on forever. I believe it’s actually playing on every single frame after it starts. My guess is I am using the wrong event handler?

How can I modify this so when the frame is entered, the sound begins and plays once, and then its over?