public ActionResult Login(RegisteredUser model, string returnUrl)
        {


            using (UsersContext entities = new UsersContext())
            {
                string username = model.UserName;
                string password = model.Password;
                Debug.AutoFlush = true;

                // Now if our password was enctypted or hashed we would have done the
                // same operation on the user entered password here, But for now
                // since the password is in plain text lets just authenticate directly
                var currentUser = entities.RegisteredUsers.SingleOrDefault(user => user.UserName == username);
                bool userValid=false; 
                if (currentUser != null) { 
                    userValid = currentUser.UserName.Equals(username) && currentUser.Password.Equals(password);
                }
                // User found in the database
                if (userValid)
                {

                    FormsAuthentication.SetAuthCookie(username, false);
                    if (Url.IsLocalUrl(returnUrl) && returnUrl.Length > 1 && returnUrl.StartsWith("/")
                        && !returnUrl.StartsWith("//") && !returnUrl.StartsWith("/\\"))
                    {

                        return Redirect(returnUrl);
                    }
                    else
                    {
                        UsersContext db = new UsersContext();
                        RegisteredUser registeredUser = new UsersContext().RegisteredUsers.SingleOrDefault(user => user.UserName == username);
                        registeredUser.IsActivated = "Yes";
                        db.Entry(registeredUser).State = EntityState.Modified;
                        db.SaveChanges();
                        return RedirectToAction("Index", "Home");
                    }
                }
                else
                {
                    ModelState.AddModelError("", "আপনার নাম অথবা পাসওয়ার্ডটি ভুল হয়েছে.");
                }
            }


            // If we got this far, something failed, redisplay form
            return View(model);

        }
        public ActionResult ExternalLoginConfirmation(RegisterExternalLoginModel model, string returnUrl)
        {
            string provider = null;
            string providerUserId = null;

            if (User.Identity.IsAuthenticated || !OAuthWebSecurity.TryDeserializeProviderUserId(model.ExternalLoginData, out provider, out providerUserId))
            {
                return RedirectToAction("Manage");
            }

            if (ModelState.IsValid)
            {
                // Insert a new user into the database
                using (UsersContext db = new UsersContext())
                {
                    UserProfile user = db.UserProfiles.FirstOrDefault(u => u.UserName.ToLower() == model.UserName.ToLower());
                    // Check if user already exists
                    if (user == null)
                    {
                        // Insert name into the profile table
                        db.UserProfiles.Add(new UserProfile { UserName = model.UserName });
                        db.SaveChanges();

                        OAuthWebSecurity.CreateOrUpdateAccount(provider, providerUserId, model.UserName);
                        OAuthWebSecurity.Login(provider, providerUserId, createPersistentCookie: false);

                        return RedirectToLocal(returnUrl);
                    }
                    else
                    {
                        ModelState.AddModelError("UserName", "User name already exists. Please enter a different user name.");
                    }
                }
            }

            ViewBag.ProviderDisplayName = OAuthWebSecurity.GetOAuthClientData(provider).DisplayName;
            ViewBag.ReturnUrl = returnUrl;
            return View(model);
        }