my $query = CGI->new();

if ($query->param( "button" ) eq 'first') { display_first(  $query ) }

##</code><code>##

my $region = $query->param( "region" ) || 42;
my $button = $query->param( "button" ) || '';
if ($button eq 'first') { # '' gives no warning

##</code><code>##

my $handler = $handlers{$query->param( "button" )};