Use case name           Select a song from a CD

        Participating Actor     Customer

        Entry condition         1. List of songs on a CD must be displayed.

                                2. Customer must have at least 50 cents credit.

        Flow of events          3. Using up and down arrow keys, customer
                                   moves highlight to desired song on the
                                   list. The list might need to be scrolled
                                   up or down in the screen to facilitate this.

                                4. User presses the SELECT key.

                                5. Information about the selected song and CD is
                                   retrieved: position of CD in jukebox carousel,
                                   location of selected song track on CD, playing
                                   time duration.

                                6. The retrieved information is put at the end
                                   of a queue used to hold song selections in order.

                                7. 50 cents is deducted from the customer's credit.

                                8. Refresh the display of the customers credit and
                                   the display of the songs queued up to be played.

        Exit condition          9. Song has been queued and should play when its
                                   turn arrives.

        Special requirements    Customer may cancel selection by pressing cancel
                                or by pressing coin return. (See Coin Return)