if (navigator.userAgent.indexOf("Mac") >=0) {
   if ((navigator.userAgent.indexOf("MSIE")>=0)&&(navigator.userAgent.indexOf("5.")>=0)) {
      document.write("<LINK REL=STYLESHEET TYPE='text/css' HREF='styles/styles_macie5.css'>");
   } else { document.write("<LINK REL=STYLESHEET TYPE='text/css' HREF='styles/styles_mac.css'>");}
} else {
   if  (navigator.appName=="Netscape") {
      document.write("<LINK REL=STYLESHEET TYPE='text/css' HREF='styles/styles_pcnn.css'>");
   } else { document.write("<LINK REL=STYLESHEET TYPE='text/css' HREF='styles/styles_pcie.css'>"); }
}