How to play sound?

Hello all,

I have a small problem, I hope actionscript expert can give me a solution.

I have two files as: A.swf and B.swf

A.swf Code:
mc.loadMovie(‘B.swf’); // mc is blank movie clip on the stage

B.swf Code:
var mySound_sound = new Sound();
mySound_sound.attachSound(“music”); // music is the linkage name of sound
mySound_sound.start();

While I am playing B.swf then music is plays perfectly. While I load it to in A.swf then music in not playing.

//NOTE: I don’t want to change anything in B.swf like new Sound(this). I want actionscript code only for A.swf

I hope you can give me a solution for this problem?