public RedirectResult SignOut()
        {
            string[] myCookies = HttpContext.Request.Cookies.AllKeys;
            foreach (string cookie in myCookies)
            {
                var httpCookie = HttpContext.Response.Cookies[cookie];
                if (httpCookie != null)
                    httpCookie.Expires = DateTime.Now.AddDays(-1);
            }
            Session.Clear();
            string redirectUrl = System.Configuration.ConfigurationManager.AppSettings["Path"].ToString();
            return Redirect(redirectUrl);
        }