A lot changes

1. able to add new courses
2. able to remove courses
3. able to edit courses
4. new requirement for adding new courses
5. can view homework and test accordingly to the button clicked
6. remove the detail mode
7. change all the JDialog to JPanel.
8. Loading all the courses in to MyCourse objects
9. Can add courses from a XML file from anywhere in the harddriver, only XML format will work.