Select Code to Download

    ...
    $mech->follow_link( text => "Add as Friend");
...
        $mech->field('group', 'Friends' );

    $mech->click_button(name => 'action_invite');

<form method="post" action="my_friends_invite_user">
  <input type="hidden" name="friend_id" value="JMwzlfI6UQU">
...
      <td class="formField"><input type="submit" name="action_invite" 
+value="Send Invite"></td>
    </tr>
  </form>