Use ReceiveData to get the return code and check that juke_box_stop_music command
was successful. Note: The tune does not stop if it is still playing
on another channel. In this situation, it stops when a juke_box_stop_music command
has been received by the custom server from each of the channels on
which the tune is playing. (In effect, the custom server needs to
receive a juke_box_stop_music command for
every juke_box_start_music command that
was issued.)