Password restriction to web pages

Normally we want our web pages to be viewable by any browser, anywhere.
From time to time there are reasons to restrict certain web pages,
e.g., to students of a particular class, or to
the folks who are developing the web site.

Amath supports password & domain restriction:

Allow one username/password only
more users/passwords
Group(s) of users
Domain restriction

SAMPLE: To view this page, you must use the username ``isaac'' and the password ``newton''.