Modify the programs given in Lab 8, server_book.cs and client_book.cs, such that a client can enter a student ID like 'U101' and the server returns his/her major 'PHYSICS'. The client will automatically send the returned major back to the server in order to get the major's average GPA using the same XML file. Then, the client displays the major of the input student and the major's average GPA.

Also change the server program such that it allows no more than two clients to be connected at any point of time.