public ActionResult DeleteTopicConfirmed(int?id)
        {
            try
            {
                if (id == null)
                {
                    return(new HttpStatusCodeResult(HttpStatusCode.BadRequest));
                }

                if (!adminServices.CanDeleteTopic(Convert.ToInt32(id)))
                {
                    return(Json(new { Message = "No se puede eliminar esta temática porque tiene al menos un ejercicio asignado." }));
                }

                adminServices.DeleteTopic(id);
                return(Json(new { Url = "/Administrator/ControlPanel" }));
            }
            catch
            {
                return(new HttpStatusCodeResult(HttpStatusCode.InternalServerError));
            }
        }