HttpSessionState.Abandon Method ()
Cancels the current session.
Assembly: System.Web (in System.Web.dll)
Session identifiers for abandoned or expired sessions are recycled by default. That is, if a request is made that includes the session identifier for an expired or abandoned session, a new session is started using the same session identifier. You can disable this by setting regenerateExpiredSessionId attribute of the configuration element to true. For more information, see Session Identifiers.
Available since 1.1