Using unloadMovieNum(); to make swf close itself

OK this should be simple, but the solutions I had found didn't work, so maybe I'm doing something different.

I'm using AS2 (still) and have 2 swfs loaded onto the main stage at different levels.

eg:

loadMovieNum("swfs/navbar.swf", 300);
loadMovieNum("swfs/info.swf", 350);

I have a button on "info.swf" which needs to close that clip (unload it completely) when the user is done with it.

Have tried:

on(release) {this.unloadMovie(); }

That didnt work, nor did:

on (release) {
unloadMovieNum(350);
}

Any help appreciated