public ActionResult DeleteAll(string id)
        {
            try
            {
                rep.DeleteAll();
                rep.Save();

                return(RedirectToAction("Index"));
            }
            catch (Exception e)
            {
                if (this.HttpContext.IsDebuggingEnabled)
                {
                    ModelState.AddModelError(string.Empty, e.ToString());
                }
                else
                {
                    ModelState.AddModelError(string.Empty, "some technical error happened");
                }
                return(View());
            }
        }