movie clip getting main movie to next frame?

Hi, I'm looping a movie clip to test if my game score is greater than 300, then trying to get it to tell the MAIN movie to go the next frame. It works if I place the actionscript on the main stage, but not when it's in a seperate movie clip. Do I have to use a tell target? How do I get the MC to tell the main movie to go the next frame? Any help would be great!

Tell Target= "_level0"
Go to and Play "Frame"
End Tell

You can also do this:

tellTarget ("/") {
nextFrame ();
}