sub get_customer
{
   my ($customer_id) = @_;

   my $dbh = WebDB::connect ();
   my $sth = $dbh->prepare ("SELECT * FROM Shipments WHERE customer_id = ?");
   $sth->execute($customer_id);
   my @customer;               ### <-- this was missing
   while (my $track_ref = $sth->fetchrow_hashref ()){
      push(@customer, $track_ref);
   }
   return(\@customer);
}