Section.java is the envelope for the description of a Section of the trackplan. All other classes are components of a Section. They are broken out to be more manageable. Each component must support methods for the following categories of actions: 1. creation with default values 2. changing of values from a pop-up dialog 3. parsing and changing of values from an XML document 4. saving of values to an XML document 5. visual presentation on the Swing view model