class->neu(\%in3);

sub neu { 
   $class = shift;
   $hash_ref = shift;
   my %hash = %{$hash_ref};

   print "Content-type: text/html ";
   print $hash{firma};
}

$class->neu(%in3);

sub neu { 
  my ($class,%neu) = @_;

  print "Content-type: text/html ";
  print $neu{firma};
}