After this database has been created successfully, the login controls
can use it. For example, when you create a new account using the
CreateUserWizard control, records are inserted in the Memberships and
Users tables. Similarly, when you try to log in, your username and password
are checked against these tables.
To force the ASP.NET run time to use forms-based authentication (which the configured Membership
provider uses under the hood), you need to set the mode attribute of the authentication element to
Forms in the Web.config file :