% my $user_agent = $r->headers_in->{'User-Agent'};

% if ($user_agent =~ /MSIE/) {
  <img src="/icons/get_netscape.gif">This site best viewed with
  <a href="http://www.netscape.com/">Netscape Navigator.</a>
% } elsif ($user_agent =~ /^Mozilla/) {
  <img src="/icons/get_msie.gif">This site best viewed with
  <a href="http://www.microsoft.com/">Microsoft Internet Explorer.</a>
% } else {
  <img src="/icons/get_amaya.gif">This site best viewed with  
  <a href="http://www.w3.org/">Amaya.</a>
% }