1  Set Up, Callbacks, Appending
 2  ----------------------------
 3  
 4  The choice/list should contain "Apple" and "Banana" for
 5   starters.
 6  
 7  Watch for "Popup!" printed to stdout when you click the choice item.
 8  
 9  When you use "Reset", the content should change to "Alpha", "Beta",
10   and "Gamma", and selecting them should install the word plus
11   "for Reset" into the text field.
12