function sniffer (language) {
  var path= "intro.htm";
  var version= navigator.appVersion;
  var urlIE= "http://www.microsoft.com/downloads/details.aspx?FamilyID=1e1550cb-5e5d-48f5-b02b-20b602228de6&displaylang=en";
  var urlNS= "http://channels.netscape.com/ns/browsers/download.jsp";
  switch (navigator.appName) {
    case "Microsoft Internet Explorer" :
    var vPosition= version.search("MSIE") + 5;
    version=version.charAt(vPosition);
    if (version > "4") location.href= path;
    else {
      if ((navigator.userLanguage == "de")||(navigator.language == "de")) document.write("Ihr Internet Explorer ist veraltet, bitte downloaden Sie sich eine" +
      " <a href=\"" + urlIE + "\" target=\"_blank\">neuere Version !!!</a>");
      else document.write("Your Internet Explorer is outdated, please download the <a href=\"http://download.microsoft.com/download/IE60/fnlrtw/ie6/W98NT42KMe/DE/ie6setup.exe\" target=\"_blank\">latest release !!!</a>");
    }
    break;
    case "Netscape" :
    version= parseInt(version);
    if (version > "4") location.href= path;
    else {
      if ((navigator.language == "de")||(navigator.language == "de-DE")) document.write("Ihr Netscape ist veraltet, bitte downloaden " +
      "Sie sich eine <a href=\"ftp://ftp.sharewarecenter.de/web_u_net/N6Setup.exe\" target=\"_blank\">neuere Version !!!</a>");
      else document.write("Your Netscape is outdated, please download the <a href=\"ftp://ftp.sharewarecenter.de/web_u_net/N6Setup.exe\" target=\"_blank\">latest release !!!</a>");
    }
    break;
    default:
    switch (language) {
      case "german" :
      document.write("Diese Webseite wurde f&uuml;r Internet Explorer 5.5 / Netscape 6.0 oder aufw&auml;rts optimiert.<br>\n" +
      "Sie verwenden keinen dieser Browser, es kann also zu Fehlern in der Dartsellung kommen !!!<br><br>\n<a href=\"" + path + "\">...weiter</a>");
      break;
      default:
      document.write("This Website is optimized for Internet Explorer 5.5 / Netscape 6.0 or higher.<br>\n" +
      "You don't use one of them, so the presentation can be incorrect !!!<br><br>\n<a href=\"" + path + "\">...forward</a>");
    }
  }
}