public ActionResult Create(cdk_users cdk_users)
        {
            if (ModelState.IsValid)
            {
                db.cdk_users.Add(cdk_users);
                db.SaveChanges();
                return RedirectToAction("Index");
            }

            return View(cdk_users);
        }
 public ActionResult Edit(cdk_users cdk_users)
 {
     if (ModelState.IsValid)
     {
         db.Entry(cdk_users).State = EntityState.Modified;
         db.SaveChanges();
         return RedirectToAction("Index");
     }
     return View(cdk_users);
 }