Nathe, there's a better solution than going through each item in the list.
Michael explained it in his previous post:
it can be done that way, with listeners, but you would need to add a listener to each list,
in case a quantity was clicked (or make the quantity lists not selectable).
alternative, in setting their selection models the same is only 2 lines of code.
Assignment instructions if I'm not mistaken is to have the dvdlist and blueray list not selectable.
Since you're using a listener for the movieslist, listbox01.getSelectedIndex() will return the exact index of the movie selected.
See if you can improve that code to 2-3 lines without any loops.