public ActionResult CreateRevision(int?id)
        {
            if (id.HasValue && MainObject.CheckUserHasWriteAccess(id.Value))
            {
                int?newId = MainObject.CreateRevision(id.Value);
                if (newId.HasValue)
                {
                    return(RedirectToAction("Index", new { id = newId }));
                }
            }

            return(RedirectToAction("Index", "Home"));
        }