This delegate represents an event handler for the DefaultAuthenticationModule.Authenticate event. It provides a custom DefaultAuthenticationEventArgs object with a reference to the current System.Web.HttpContext. This event handler must be coded in the global.asax, using the event name DefaultAuthentication_OnAuthenticate (and it does not need to be connected with a Handles keyword or the AddHandler( ) command).
public delegate void DefaultAuthenticationEventHandler(object sender, DefaultAuthenticationEventArgs e);