stopping sound without a button

Is it possible to stop a sound playing without a button?  I have background music on frame 1 but before I move onto frame 2 I want the sound to stop. I have 5 buttons on frame 1 to lead to different frames but I do not want them to control the sound. I also do not want to use stop all sounds on the next frame as I want sounds to work on those pages. The script below is to start the sound so how do I stop it from continuing onto the next frames when the control buttons are clicked.

import flash.media.SoundChannel; 
var sc:SoundChannel=new SoundChannel(); 
sc=new walk().play();