Log Out Funcationality in ASP.Net

to implement the log out functionality in asp.net application use the following code in the body of log out button event handler

                Session.Clear();
                Session.Abandon();
                Response.Clear();
                Response.Redirect(context.LoginPage);
and to prevent back feature of the browser or accessing the website after log out using the following line

                HttpContext.Current.Response.Cache.SetExpires(DateTime.Now);