ASP.NET - security with asp.net

Hello all
I have some web site have a login screen to allow the user login to the site using user name and password , and this login saved in the DB , but there's some strange thing happen with me that 's if some one doesn't have a permissin (user name or password) and copy some URL of some page in my site and paste it to the web browser  he can see the conent of the page , I want any one doesnt have a permission do that redirected to the login page , please if any body get what I mean and can help me please send me or tell me about some URL may help me in doing that
Regards
Mostafa

Hi,

ASP.NET, in conjunction with Microsoft Internet Information Services (IIS), can authenticate user credentials such as names and passwords using any of the following authentication methods:

• Windows: Basic, digest, or Integrated Windows Authentication (NTLM or Kerberos).
• Microsoft Passport authentication
• Forms authentication
• Client Certificate authentication

For more information please refre to the below link.

http://msdn.microsoft.com/en-us/library/330a99hc%28v=vs.71%29.aspx

Hope it helps you.