public ActionResult Login(User user)
        {
            var returnUrl = TempData["ReturnUrl"];
            if (ModelState.IsValid)
            {
                if (UserManagement.IsValid(user.Username, user.Password))
                {
                    var validUser = UserManagement.GetValidUserList().Single(x => x.UserName == user.Username);
                    FormsAuthentication.SetAuthCookie(user.Username, user.RememberMe);
                    Session["User"] = new UserLoginDto { Username = user.Username, Id = validUser.Id, IsAdmin = validUser.IsAdmin};
                    if (validUser.IsAdmin)
                    {
                        return RedirectToAction("Dashboard", "Admin");
                    }

                    if (returnUrl != null && !string.IsNullOrEmpty(returnUrl.ToString()))
                    {
                        return Redirect(returnUrl.ToString());
                    }
                    return RedirectToAction("ProductView", "Product");
                }

                if (!UserManagement.IsValidUsername(user.Username))
                {
                    ModelState.AddModelError("Username", "This username cannot be found.");
                }
                else
                {
                    ModelState.AddModelError("Password", "Password is incorrect!");
                }
                TempData["ReturnUrl"] = returnUrl;
            }
            return View(user);
        }
 public ActionResult Login(User user)
 {
     if (ModelState.IsValid)
     {
         if (UserManagement.isValid(user.Username, user.Password))
         {
             if (UserManagement.IsAdmin(user.Username, user.Password))
             {
                 FormsAuthentication.SetAuthCookie(user.Username, user.RememberMe);
                 Session["User"] = new UserLoginDTO { Username = user.Username };
                 return RedirectToAction("AdminPage", "User");
             }
             FormsAuthentication.SetAuthCookie(user.Username, user.RememberMe);
             Session["User"] = new UserLoginDTO { Username = user.Username };
             return RedirectToAction("CustomerPage", "User");
         }
         ModelState.AddModelError("General", "Password is incorrect!");
     }
     return View(user);
 }