For the questions below, imagine that you want to implement a "Movie Cost" program that will use a GUI to obtain from the user the time of the movie and the number of people that need tickets, and will compute the cost. The GUI will use a JComboBox to obtain the time of movie (one of "Matinee", "Rush hour" or "Normal") and a JSlider to obtain the number of people (the JSlider goes from 1 to 10 and defaults to 1) and a JButton that says "Compute".
Why would you not need to implement a ChangeListener for the JSlider?