if ((navigator.appName == "Netscape") && ((parseInt(navigator.appVersion) == 4) || (parseInt(navigator.appVersion) == 5))) {
  document.write("<link rel='stylesheet' href='css/styleNS.css' type='text/css'>");
} else {
  document.write("<link rel='stylesheet' href='css/styleNS.css' type='text/css'>");
}