if (action.equals("login")) {

            String email = request.getParameter("usernamelogin");
            String password = request.getParameter("passwordlogin");
            String checkEmail;
            String checkPassword;
            String checkSalt;
            String checkHashedPassword;
            //finish success

            User user = UserDB.select(email);
            if (user != null) {
                checkEmail = user.getEmail();
                checkPassword = user.getPassword();
                checkSalt = user.getSalt();
                try {
                    checkHashedPassword = PasswordUtil.hashAndSaltPassword(password, checkSalt);
                    if (checkPassword.equals(checkHashedPassword)) {
                        session.setAttribute("user", user);
                        success = true;
                        ArrayList<Tweet> tweets = TwitterDB.selectTweets(user.getUserName());
                        ArrayList<Tweet> mentionTweets = TwitterDB.selectTweetMentions(user.getUserName());
                        ArrayList<Tweet> totalTweets = new ArrayList<Tweet>();
                        totalTweets.addAll(tweets);
                        totalTweets.addAll(mentionTweets);
                        Collections.sort(totalTweets);
                        session.setAttribute("tweets", totalTweets);
                        session.setAttribute("success", success);

                        ArrayList<User> users = UserDB.selectUsers(user.getUserName());
                        session.setAttribute("users", users);

                        url = "/home.jsp";
                    } else {
                        message = "login failed";
                        session.setAttribute("message", message);
                        url = "/login.jsp";
                    }
                } catch (NoSuchAlgorithmException ex) {
                    Logger.getLogger(membershipServlet.class.getName()).log(Level.SEVERE, null, ex);
                }

            } else {
                message = "login failed";
                session.setAttribute("message", message);
                url = "/login.jsp";
            }
        }