if (navigator.appVersion.indexOf("Mac") != -1) {
  if (navigator.appName == 'Netscape') {
  	if (navigator.appVersion.charAt(0) == "5"){
	  document.write('<LINK REL="stylesheet" HREF="css/pc_ie.css" type="text/css">');
	} else{
   document.write('<LINK REL="stylesheet" HREF="css/mac_ns.css" type="text/css">');
	}
  } else {
   document.write('<LINK REL="stylesheet" HREF="css/mac_ie.css" type="text/css">');
  }
 } else {
  if (navigator.appName == 'Netscape') {
  	if (navigator.appVersion.charAt(0) == "5"){
	  document.write('<LINK REL="stylesheet" HREF="css/pc_ns6.css" type="text/css">');
	} else{
     document.write('<LINK REL="stylesheet" HREF="css/pc_ns.css" type="text/css">');
	}
  } else {
   document.write('<LINK REL="stylesheet" HREF="css/pc_ie.css" type="text/css">');
  }
 }