use strict;
use GGI;

my $cgi = new CGI;
my $state = $cgi->param("state");
my $pack;
if ( $state eq "W" ) {
  $pack = 'Pack_W';
  use Pack_W;
} elsif ( $state eq "X" ) {
  $pack = 'Pack_X';
  use Pack_X;
} elsif ( $state eq "Y" ) {
  $pack = 'Pack_Y';
  use Pack_Y;
} elsif ( $state eq "Z" ) {
  $pack = 'Pack_Z';
  use Pack_Z;
}

my $app = $pack->new(%stuff);
$app->run;