%states = ( AL => ['AL', 'Alabama'],
            AK => ['AK', 'Alaska'],
...
            SA => ['SA', 'Saskatchewan'],
            YU => ['YU', 'Yukon Territory'],
);
if (my $st = $states{$FORM{state}})
{
  ($state,$statename)=@$st;
}
else
{
  die "Invalid state!"
}