Div Lights Fade Script - Not working on Mac?

I have a little javascript/css script that fades my website to black, except for the video in the middle, to give a sort of theatre effect

Example : http://www.animefushigi.com/bleach-episode-293

Click LIGHTS OUT

The script adds a black overlay on the entire page except for the "vidboxx" div.

Some people say that it is working, but not for m开发者_JS百科e

Screenshot http://img231.imageshack.us/img231/5963/firefoxscreensnapz002.png

Any suggestions on how to fix?

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Add a z-index to "vidboxx", which is higher than the z-index of black overlay. Example:

#black-overlay: z-index:100;
#vidboxx      : z-index:101;

with Javascript, z-index is accessible by yourelementhere.style.zIndex