Script for targeting platforms (not browsers)

I can’t seem to get a straight answer for this, not sure what I’m doing wrong, but have been searching for a solution for over a month.

I need to call separate stylesheets, pending on the platform (not browser). I have a script I’ve found that’s supposed to do that, but it’s not working.

The site is fish-fry.com/dev

the script, which I’ve placed in my head is:

<script type="text/javascript">

/***********************************************
* Different CSS depending on OS (mac/pc)- © Dynamic Drive (www.dynamicdrive.com)
* This notice must stay intact for use
* Visit http://www.dynamicdrive.com/ for full source code
***********************************************/

var csstype="external" //Specify type of CSS to use. "Inline" or "external"

var mac_externalcss='http://www.fish-fry.com/dev/wp-content/themes/FISH-FRY-MUSIC-AND-SOUND-CUSTOM-THEME/style.css' //if "external", specify Mac css file here
var pc_externalcss='http://www.fish-fry.com/dev/wp-content/themes/FISH-FRY-MUSIC-AND-SOUND-CUSTOM-THEME/style-windows.css' //if "external", specify PC/default css file here

///////No need to edit beyond here////////////

var mactest=navigator.userAgent.indexOf("Mac")!=-1
if (csstype=="inline"){
document.write('<style type="text/css">')
if (mactest)
document.write(mac_css)
else
document.write(pc_css)
document.write('</style>')
}
else if (csstype=="external")
document.write('<link rel="stylesheet" type="text/css" href="'+ (mactest? mac_externalcss : pc_externalcss) +'">')

</script>

Any help is greatly appreciated!

[ Duplicate http://wordpress.org/support/topic/radical-difference-between-mac-and-pc?replies=16 closing. Please keep to the original thread for this topic. ]