Are you talking about
Asp.net
pages? (You put
Asp.net
tag for the question).
If that is so, then, the
Forms Authentication
lets you implement this very easily.
Please skip this answer if you are really talking about
ASP
pages (
Not Asp.net pages)
If you use
Form Authentication
for Authentication, you just need to implement Authorization in your
Asp.net
application to implement this.
Forms Authorization
lets you configure the page access to authenticated users very easily, in the
web.config
file.
See
http://msdn.microsoft.com/en-us/library/ff647070.aspx[
^] to learn more about this.