I want to use forms authentication in my .NET application. How do I go about doing this?
Not sure if this answers your question but if this is a new project I would highly recommend using ASP.NET Membership stuff.
ASP.NET membership enables you to validate and manage user information for your Web application. It provides functionality for validating user credentials, creating and modifying membership users, and managing user settings such as passwords and e-mail addresses. ASP.NET membership is primarily intended for use with ASP.NET forms authentication, but can be used anywhere within an ASP.NET application.
Managing Users by Using Membership