User « Authentication Authorization « ASP.NET Tutorial

21.15.1.Getting the username of the logged-in user
21.15.2.Checking whether the user is authenticated
21.15.3.Using an If/Then statement that checks authentication
21.15.4.Using the AuthenticationType property
21.15.5.Checking whether the user is part of a specific role
21.15.6.Using the WindowsBuiltInRole enumeration
21.15.7.Output the name of the currently logged-on user as authenticated by the ASP.NET application