Loaded swf won't stop sound

programming flash
1

Hi
I’m very new to flash codes and I try to develop program that works on CD

I made main swf that load external swf . In main swf that is a button in the main list that lead to goto other frame load the external swf in uiload

The problem when I go back to main list that external swf sound wont stop
I tried this code

SoundMixer.stopAll();

It works but it also stop background sound in the main frame

Thanks in advance