i create one power point with full of internal hyperlink  which go around all 
my slide. i add a music (mp3) to be continuously play all the time. No 
problem with that. But one of my slide contain video in it. So when the video 
played, the music does not stop. How can i stop the music when the video 
played or at least it will stop when enter the video slide? 
The "stop playing" function only provide in 3 cases:
on click, after current slide, after xx slide..
The first two is really not suitable. I can't use after xx slide bcoz i use 
hyperlink. so If the person click on the hyperlink, the counting will be 
different so it will stop faster or maybe not stop when it reach the video 
slide