use CGI;
my $query = new CGI;
$param = $query->param('raum');
if ($param =~ /^[A-Za-z]+$/) {
  my $retcode = system('/shares/www/cgi-bin/rolladen_conf.pl', "raum=$param");
  die "system failed: $?" if $retcode != 0;
}
else {
  print "Rollladen ok"
}