print "carrier,boxno,listno,shipno,custno\n";
while (my  $hash_ref = $sth->fetchrow_hashref) {
  print "$hash_ref->{carrier},";
  print "$hash_ref->{boxno},";
  print "$hash_ref->{listno},";
  print "$hash_ref->{shipno},";
  print "$hash_ref->{custno}\n";
}