Music in Loaded movies

I have a project where I have to load other flash movies into it as a "porfolio"

So as of right now the code I have when clicking on the christmasCardBtn is

    myLoader1.load(new URLRequest("christmasCard.swf"));
    addChild(myLoader1);

This is working fine to load the movie. I also have a button that appears when a movie is loaded that is coded to remove the myLoader1 child when selected. So the movie dissapears. But there are a few of my movies that have on-going sound clips. How do I make the sound turn off when the button to remove the movie is selected?

I tried adding SoundMixer.stopAll(); to the button that removes the movie but this doesn't work. I'm assuming I need to unload the movie by my textbook is scarce on details of this.

Any suggestions? Thank you!