Sign out problem in SharePoint 2010

I solved my problem :)

  if (HttpContext.Current.Request.Cookies["FedAuth"] != null)
  {
    HttpCookie requestCookie = new HttpCookie("FedAuth");
    requestCookie.Secure = false;
    requestCookie.Expires = DateTime.Now.AddYears(-1);
  }
            FederatedAuthentication.SessionAuthenticationModule.SignOut();
FormsAuthentication.SignOut();

Response.Redirect("~/redirecturl");