Senario Name: ReturnVideo2: One late return

Participating actors: Bob: Customer, Lisa: cashier

Flow of events:
1. Bob arrives at the counter and hands "The Matrix" and "2001" to Lisa.  Lisa presses "return video" button. 

2. The system asks for a membership id. Lisa asks for Bob's membership card and scans it, entering his 		
   membership id, "438". 

3. The system retrieves Bob's account and displays it to Lisa. Below the account information the system asks
   for the serial number of a returned video.

4. Lisa scans the barcode on "2001", entering the serial number 12344 for this copy. 
   
5. The system retrieves rental transaction 050219, documenting Bob's rental of "2001" and "The Matrix", and
   displays it to Lisa.

6. Lisa sees that "2001", serial number 12344, has been removed from rental transaction 050219, that he has no 
   late fees due, and that he has one other video, "The Matrix", rented out. The system prompts Lisa for the 
   serial number of the next returned video.

7. Lisa scans the barcode on "The Matrix", entering the serial number 50001 for this copy.

8. Lisa sees that "The Matrix", serial number 50019, has been removed from rental transaction 050219. The system 
   tells Lisa that "the Matrix" was due back two days earlier and that Bob has $4.00 in late fees to pay. 
   He has no other videos rented out under this transaction.    

9. Lisa informs Bob of his late fees and asks if he would like to pay now or later.

10. Bob says he will pay later. He retrieves his membership card, thanks Lisa, and leaves the store.

11. Lisa selects "save transaction."

12. The system tells Lisa that rental transaction 050219 has been saved.