I've just read the chapter of Security(Page 579) from your book "Beginning
ASP.NE T 4 in C# and VB
To quote from your book :
"ASP.NET 4 ships with a number of application services, of which the most important ones are:
Membership: Enables you to manage and work with user accounts in your system.
Roles: Enables you to manage the roles that your users can be assigned to.
Profile: Enables you to store user-specific data in a back-end database."
Actually it was my fault in understanding. Anyway I got the answer. Many thanks Imar.