Sound problems

Hi,
I attached my example code together with my post. I’m facing some problems, so i hope someone can help me.
First double click the index.swf. Then it will load the interface, mg1.swf. Then, click the button on the interface to open another swf file, which it popUp.swf. These are the problems come it. The sounds from mg1.swf and popUp.swf are playing. How do i set the sound of mg1.swf to zero while the popUp.swf is opening and set the sound back to 100 after i closed the popUp.swf?