PLEASE HELP! Flash mx(6) action scripting help with css

I need some help rewriting this js code to work inside a flash movie - I need my dynamic content to pick up the proper css depending on what operating system they are on:

<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=“inline” //Specify type of CSS to use. “Inline” or “external”
    var mac_css=‘body{font-size: 14pt; }’ //if “inline”, specify mac css here
    var pc_css=‘body{font-size: 12pt; }’ //if “inline”, specify PC/default css here
    var mac_externalcss=’/style/macstyle.css’ //if “external”, specify Mac css file here
    var pc_externalcss=’/style/pcstyle.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>

can someone help me do this? Pleeeeeease?