show/hide using div visibility

http://www.buddhapada.com/tests/by-id.htm

WARNING: when "show content one" link is click there will be SOUND.
A looping SWF loads with sound. The sound is useful for this test.

In Firefox, the links will show/hide DIVs using a JavaScript.

"Show Content Two" displays another DIV as will "Show Content Three."

Clicking them will stop the SFW looping in the Content One Div.

BUT...in Internet Explorer, clicking on the other two links will NOT stop
the SWF and you can continue to hear the sound.

The same thing happens with any active content: QT MOV files, MP3's, MP4's.

Any thought one how to get IE to stop the content from playing as Firefox
does?