sub www_mech_deactivate {
  my $self = shift;
  my $email = shift;

  my $uid = $self->get_uid_from_email($email);
  my $path = $self->{'cfg'}->param("paths.subscription_management_page");
  $path =~ s/UID/$uid/;
  $self->{'agent'}->get($path);

  # this works to subscribe person to all lists:
  $self->{'agent'}->submit_form(
               form_number => 2,
               fields      => {
            'newsletters[65]' => '65',
            'newsletters[34]' => '34',
            'newsletters[17]' => '17',
            'newsletters[71]' => '71',
               }
           );

  # But all of these attempts fail . . . 
  $self->{'agent'}->untick('newsletters[17]');
  $self->{'agent'}->untick('newsletters[65]','');
  $self->{'agent'}->untick('newsletters[34]','checked');
  $self->{'agent'}->untick('newsletters[71]','71');

  $self->{'agent'}->submit_form( form_number => 2 );

  return;
}