public ActionResult Alta(Vehiculo vehiculo)
        {
            db.Vehiculo.Add(vehiculo);
            db.SaveChanges();

            return Json(vehiculo);
        }
        public ActionResult UpdatePost(Vehiculo vehiculo)
        {
            if (ModelState.IsValid)
            {
                db.Entry(vehiculo).State=EntityState.Modified;
                db.SaveChanges();

                return Json(vehiculo,JsonRequestBehavior.AllowGet);
            }
            return Json(vehiculo, JsonRequestBehavior.AllowGet);
        }