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

            return View(users);
        }
        public ActionResult Login(Users u)
        {
            //this action is for handle post (login)

            if(ModelState.IsValid){//this is check validity

                using(PointSaleEntities dc= new PointSaleEntities()){

                            var v= dc.Users.Where(a=>a.Nickname.Equals(u.Nickname)&& a.Password.Equals(u.Password)).FirstOrDefault();
                            if(v!=null){
                               Session["LogedUserID"]=v.Id.ToString();
                               Session["LogedUserNickname"]=v.Nickname.ToString();
                               return RedirectToAction("AfterLogin");
                            }
                     }
            }
            return View(u);
        }
 public ActionResult Edit(Users users)
 {
     if (ModelState.IsValid)
     {
         db.Entry(users).State = EntityState.Modified;
         db.SaveChanges();
         return RedirectToAction("Index");
     }
     return View(users);
 }