C:\5ja\hw2>java GradeBookTest

--- Book 1 message ---
Welcome to the grade book for
English 293A!
This course is presented by: Wilbur Shakelance

--- Book 2 data ---
Book 2 course name: Physics 172
Book 2 instructor: Alvin Einmug

--- Book 1 message and data after changes ---
Welcome to the grade book for
English 293B!
This course is presented by: Marv Train
   New course name: English 293B
   New instructor: Marv Train