Comp 272 Programming assignment 3	Dordal	 Feb 21, 2001
Due: Friday, Mar 2

Take the mail system program, and make the following changes.
The program, mail.cpp, is available on my web page.
It contains my version of getline(); keep this in mind if you
instead decide to download from the author's web page.

1. In the existing version, all input is handled by the mailbox,
once the user enters the extension. The mailsystem class makes no
further use of InputReader.

Change this so that the mailsystem handles what's now in receive_message().
That is, the MailSystem class will have a receive_message function,
which will promt the user for an input message and then pass it
to the mailbox. If the user types "#", though (see the existing
receive_message for how to check this), you will invoke the login()
function **for that mailbox**.

You will need to design and implement an interface so that MailSystem
can insert a message into a given mailbox; an add_message() function
as part of class Mailbox would be the simplest.

If the user chooses to login, input will still be handled by the Mailbox.
This split of functionality (some input handled by Mailsystem, some by
Mailbox) doesn't really make sense, but do it anyway, as an illustration.


2. In the original version, when you enter the wrong password,
you don't get prompted for a new one. Change this so you do.


3. Add an option to the administrative mailbox to change the passcode
and greeting of any other mailbox.
	Press N   to change the passcode of another mailbox
	Press N+1 to change the greeting of another mailbox