diff --git a/javascript-practice/src/assets/images/favicon.ico b/javascript-practice/src/assets/images/favicon.ico
new file mode 100644
index 0000000..f77999d
Binary files /dev/null and b/javascript-practice/src/assets/images/favicon.ico differ
diff --git a/javascript-practice/src/js/constants/constant.js b/javascript-practice/src/js/constants/constant.js
index e6a63f2..9a05204 100644
--- a/javascript-practice/src/js/constants/constant.js
+++ b/javascript-practice/src/js/constants/constant.js
@@ -4,7 +4,16 @@ export const MESSAGE = {
     'Password must at least one uppercase, one lowercase letter, one number and one special character!',
   ERROR_MESSAGE_DEFAULT: 'Something went wrong!',
   TIME_OUT_ERROR: 'Connection time out! Please try again!',
-  ERROR_CREDENTIAL: 'Email or password not match! Please try again!',
+  ERROR_CREDENTIAL: {
+    title: 'Error Credential',
+    message: 'Email or password not match! Please try again!',
+  },
+  DEFAULT_TITLE_ERROR_POPUP: 'Error',
+  USER_EXIST_ERROR: 'User is exists! Please try another email!',
+};
+export const BTN_CONTENT = {
+  GOT_IT: 'Got it!',
+  OK: 'Ok',
 };
 export const TYPE_POPUP = { success: 'success', error: 'error' };
 export const MARK_ICON = { success: 'check', error: 'error' };
diff --git a/javascript-practice/src/js/controllers/loginController.js b/javascript-practice/src/js/controllers/loginController.js
index a2ae10d..322b537 100644
--- a/javascript-practice/src/js/controllers/loginController.js
+++ b/javascript-practice/src/js/controllers/loginController.js
@@ -4,20 +4,13 @@ export default class LoginController {
     this.loginView = view.loginView;
   }
 
-  handlerGetUserByEmail(email) {
-    return this.service.userService.getUserByEmail(email);
-  }
-
-  handlerCreateTokenUser(user) {
-    return this.service.userService.createTokenUser(user);
+  handlerValidateUser(email, password) {
+    return this.service.userService.validateUser(email, password);
   }
 
   init() {
     if (this.loginView.isLoginPage()) {
-      this.loginView.addHandlerForm(
-        this.handlerGetUserByEmail.bind(this),
-        this.handlerCreateTokenUser.bind(this),
-      );
+      this.loginView.addHandlerForm(this.handlerValidateUser.bind(this));
     }
   }
 }
diff --git a/javascript-practice/src/js/helpers/helpers.js b/javascript-practice/src/js/helpers/helpers.js
index f577ee1..7bb705a 100644
--- a/javascript-practice/src/js/helpers/helpers.js
+++ b/javascript-practice/src/js/helpers/helpers.js
@@ -50,3 +50,15 @@ export const createToken = () => {
   }
   return token;
 };
+
+export const convertModelToDataObject = (model) => {
+  const { id, ...data } = model;
+
+  return { id, data };
+};
+
+export const convertDataObjectToModel = (data) => {
+  const { id, ...object } = data;
+
+  return { id, ...object.data };
+};
diff --git a/javascript-practice/src/js/main.js b/javascript-practice/src/js/main.js
index 626a1f8..851ad8e 100644
--- a/javascript-practice/src/js/main.js
+++ b/javascript-practice/src/js/main.js
@@ -3,5 +3,6 @@ import App from './app';
 // Sure that scripts called after DOM loaded
 document.addEventListener('DOMContentLoaded', () => {
   const myApp = new App();
+
   myApp.start();
 });
diff --git a/javascript-practice/src/js/models/user.js b/javascript-practice/src/js/models/user.js
index 0d0536c..d46bb8a 100644
--- a/javascript-practice/src/js/models/user.js
+++ b/javascript-practice/src/js/models/user.js
@@ -1,5 +1,6 @@
 export default class User {
   constructor({ email, password, walletName = '', accessToken = '' }) {
+    this.id = User.createIdUser();
     this.email = email;
     this.password = password;
     this.walletName = walletName;
diff --git a/javascript-practice/src/js/services/commonService.js b/javascript-practice/src/js/services/commonService.js
index 55c2415..717d424 100644
--- a/javascript-practice/src/js/services/commonService.js
+++ b/javascript-practice/src/js/services/commonService.js
@@ -1,4 +1,8 @@
-import { timeOutConnect } from '../helpers/helpers';
+import {
+  convertDataObjectToModel,
+  convertModelToDataObject,
+  timeOutConnect,
+} from '../helpers/helpers';
 import FirebaseService from './firebaseService';
 
 export default class CommonService {
@@ -7,32 +11,59 @@ export default class CommonService {
     this.firebaseService = FirebaseService;
   }
 
+  /**
+   * Connect to Firebase Databse
+   */
   connectToDb() {
     this.firebaseService.reconnect();
   }
 
-  async findKeyByProperty(property, value, path = this.defaultPath) {
+  async getDataFromProp(property, value, path = this.defaultPath) {
     this.connectToDb();
-    const existUser = this.firebaseService.findKeyByPropery(
+    const existUser = this.firebaseService.getDataFromProp(
       path,
       property,
       value,
     );
     const result = await timeOutConnect(existUser);
-    return result;
+
+    if (result.id && result.data) {
+      return convertDataObjectToModel(result);
+    }
+
+    return null;
   }
 
-  async save(data, path = this.defaultPath) {
+  /**
+   * Save data on database
+   * @param {*} data The data wants to save on database
+   * @param {string} path The path of database
+   */
+  async save(model) {
     this.connectToDb();
-    const saveUser = this.firebaseService.save(data, path);
-    await timeOutConnect(saveUser);
+    const results = convertModelToDataObject(model);
+
+    const saveData = this.firebaseService.save(
+      results.data,
+      this.defaultPath + results.id,
+    );
+
+    await timeOutConnect(saveData);
   }
 
+  /**
+   *
+   * @param {string} id The string of data object
+   * @param {string} path The path of database
+   * @returns {Object || null} Return the object if has, otherwise return null
+   */
   async getDataFromId(id, path = this.defaultPath) {
     this.connectToDb();
     const result = await this.firebaseService.getDataFromId(id, path);
     const data = await timeOutConnect(result);
+
     if (data) return data;
+
     return null;
   }
 }
diff --git a/javascript-practice/src/js/services/firebaseService.js b/javascript-practice/src/js/services/firebaseService.js
index d65b544..80d2036 100644
--- a/javascript-practice/src/js/services/firebaseService.js
+++ b/javascript-practice/src/js/services/firebaseService.js
@@ -43,28 +43,30 @@ class FirebaseService {
   }
 
   /**
-   * Find the key of value by property in database
+   * Find id of value by property in database
    * @param {string} path The path of database to be found
    * @param {string} property The property of the value need to be found
    * @param {value} value The value to compare in database
    * @returns {Promise} Return the relsoves when find completed
    */
-  findKeyByPropery(path, property, value) {
+  getDataFromProp(path, property, value) {
     return new Promise((resolve) => {
       onValue(
         ref(this.db, path),
         (snapshot) => {
-          let result;
+          let id;
+          let data;
 
           // snapshot is a type of data by Firebase define
           snapshot.forEach((childSnapshot) => {
-            const data = childSnapshot.val();
+            const dataTemp = childSnapshot.val();
 
-            if (data[property] === value) {
-              result = childSnapshot.key;
+            if (dataTemp[property] === value) {
+              id = childSnapshot.key;
+              data = dataTemp;
             }
           });
-          resolve(result);
+          resolve({ id, data });
         },
         {
           onlyOnce: true,
@@ -73,6 +75,12 @@ class FirebaseService {
     });
   }
 
+  /**
+   * Get data object from Id
+   * @param {string} id The id of data object
+   * @param {string} path The path of data save in database
+   * @returns {Promise} Return new Promise
+   */
   getDataFromId(id, path) {
     return new Promise((resolve) => {
       onValue(
diff --git a/javascript-practice/src/js/services/userService.js b/javascript-practice/src/js/services/userService.js
index 5d6e5a1..0bcaef8 100644
--- a/javascript-practice/src/js/services/userService.js
+++ b/javascript-practice/src/js/services/userService.js
@@ -1,5 +1,4 @@
 import { createToken } from '../helpers/helpers';
-import User from '../models/user';
 import CommonService from './commonService';
 import LocalStorageService from './localStorageService';
 
@@ -15,17 +14,7 @@ export default class UserService extends CommonService {
    * @param {Object} user The user object need to be saved into databae
    */
   saveUser(user) {
-    const pathData = this.defaultPath + User.createIdUser();
-    this.save(user, pathData);
-  }
-
-  /**
-   * Get user id by email
-   * @param {string} email Email need to be check
-   * @returns {Promise || number} Return id user when exist, otherwise will undefined
-   */
-  getUserIdByEmail(email) {
-    return this.findKeyByProperty('email', email);
+    this.save(user);
   }
 
   /**
@@ -34,10 +23,12 @@ export default class UserService extends CommonService {
    * @returns {boolean} Return true if find, otherwise return false
    */
   async checkUserExist(email) {
-    const userExist = await this.getUserIdByEmail(email);
+    const userExist = await this.getUserByEmail(email);
+
     if (userExist) {
       return true;
     }
+
     return false;
   }
 
@@ -47,23 +38,49 @@ export default class UserService extends CommonService {
    * @returns {Object || null} Return new User Object if find, otherwise return null.
    */
   async getUserByEmail(email) {
-    const id = await this.getUserIdByEmail(email);
-    if (id) {
-      const user = await this.getDataFromId(id);
-      return new User(user);
+    const result = await this.getDataFromProp('email', email);
+
+    if (result) {
+      return result;
     }
+
     return null;
   }
 
-  async createTokenUser(user) {
-    const id = await this.getUserIdByEmail(user.email);
+  /**
+   * Validate user info
+   * @param {string} email The email user input
+   * @param {*} password The password user input
+   * @returns {boolean} Return true if match info on database, otherwise return false
+   */
+  async validateUser(email, password) {
+    const user = await this.getUserByEmail(email);
+
+    // Check password
+    if (user && user.password === password) {
+      // Create token for user
+      await this.createTokenUser(email);
+
+      return true;
+    }
+
+    return false;
+  }
+
+  /**
+   * Create token for user on database
+   * @param {string} email The email user need to be create token
+   */
+  async createTokenUser(email) {
+    const user = await this.getUserByEmail(email);
+    const newUserData = user;
 
     // Add token to user object
-    const newUserData = new User(user);
     newUserData.accessToken = createToken();
 
-    this.save(newUserData, this.defaultPath + id);
+    this.save(newUserData);
 
+    // Add access token to local storage
     LocalStorageService.add('accessToken', newUserData.accessToken);
   }
 }
diff --git a/javascript-practice/src/js/views/loginView.js b/javascript-practice/src/js/views/loginView.js
index 2ac412e..0733561 100644
--- a/javascript-practice/src/js/views/loginView.js
+++ b/javascript-practice/src/js/views/loginView.js
@@ -1,21 +1,20 @@
 import CommonLoginRegisterView from './commonLoginRegisterView';
-import * as CONSTANT from '../constants/constant';
+import { MESSAGE, TYPE_POPUP, BTN_CONTENT } from '../constants/constant';
 
 export default class LoginView extends CommonLoginRegisterView {
   constructor() {
     super();
 
     this.parentElement = document.querySelector('.form');
-    this.loginPage = document.getElementById('loginPage');
+    this.loginPage = document.URL.includes('/login');
   }
 
   /**
    * Get data from user input
    * @returns {Object || null} Return object or null
    */
-  getDataFromForm() {
-    const { loginForm } = document.forms;
-    const formData = new FormData(loginForm);
+  getDataFromForm(event) {
+    const formData = new FormData(event.target);
     const email = formData.get('email');
     const password = formData.get('password');
 
@@ -28,12 +27,11 @@ export default class LoginView extends CommonLoginRegisterView {
    * Implement error popup in site
    * @param {string} content The content will show in error popup
    */
-  initErrorPopup(content) {
-    const typePopup = CONSTANT.TYPE_POPUP.error;
-    const title = 'Error Credential!';
-    const btnContent = 'Got it!';
+  initErrorPopup(error) {
+    const title = error.title ? error.title : MESSAGE.DEFAULT_TITLE_ERROR_POPUP;
+    const content = error.message ? error.message : error;
 
-    this.initPopupContent(typePopup, title, content, btnContent);
+    this.initPopupContent(TYPE_POPUP.error, title, content, BTN_CONTENT.GOT_IT);
 
     // Show popup
     this.tooglePopupForm();
@@ -41,35 +39,36 @@ export default class LoginView extends CommonLoginRegisterView {
 
   /**
    * Add event listener for form input
-   * @param {Function} handler The function need to be set event
+   * @param {Function} validateUser The function need to be set event
    */
-  addHandlerForm(getUserByEmail, createTokenUser) {
+  addHandlerForm(validateUser) {
     this.parentElement.addEventListener('submit', (e) => {
       e.preventDefault();
       this.clearErrorMessage();
-      this.submitForm(getUserByEmail, createTokenUser);
+      this.submitForm(validateUser, e);
     });
   }
 
-  async submitForm(getUserByEmail, createTokenUser) {
+  /**
+   * The action when submit form
+   * @param {Function} validateUser The function need to be set event
+   */
+  async submitForm(validateUser, event) {
     try {
       // Load spinner
       this.toogleLoaderSpinner();
 
       // Get data from form
-      const userInput = this.getDataFromForm();
+      const userInput = this.getDataFromForm(event);
       // Check user exist
-      const user = await getUserByEmail(userInput.email);
+      const results = await validateUser(userInput.email, userInput.password);
 
-      if (user) {
-        // If user exist, compare password
-        if (userInput.password === user.password) {
-          await createTokenUser(user);
-          window.location.replace('/');
-          return;
-        }
+      if (results) {
+        window.location.replace('/');
+
+        return;
       }
-      throw Error(CONSTANT.MESSAGE.ERROR_CREDENTIAL);
+      throw MESSAGE.ERROR_CREDENTIAL;
     } catch (error) {
       // Show popup error
       this.initErrorPopup(error);
@@ -79,6 +78,6 @@ export default class LoginView extends CommonLoginRegisterView {
   }
 
   isLoginPage() {
-    return this.loginPage !== null;
+    return this.loginPage;
   }
 }
diff --git a/javascript-practice/src/js/views/registerView.js b/javascript-practice/src/js/views/registerView.js
index 3a26d6b..7470dd2 100644
--- a/javascript-practice/src/js/views/registerView.js
+++ b/javascript-practice/src/js/views/registerView.js
@@ -1,4 +1,4 @@
-import { TYPE_POPUP } from '../constants/constant';
+import { TYPE_POPUP, MESSAGE, BTN_CONTENT } from '../constants/constant';
 import CommonLoginRegisterView from './commonLoginRegisterView';
 import User from '../models/user';
 
@@ -6,7 +6,7 @@ export default class RegisterView extends CommonLoginRegisterView {
   constructor() {
     super();
 
-    this.registerPage = document.getElementById('registerPage');
+    this.registerPage = document.URL.includes('/register');
   }
 
   /**
@@ -24,8 +24,10 @@ export default class RegisterView extends CommonLoginRegisterView {
 
     if (this.validateForm(account)) {
       const user = new User(account);
+
       return user;
     }
+
     return null;
   }
 
@@ -48,12 +50,11 @@ export default class RegisterView extends CommonLoginRegisterView {
    * Implement error popup in site
    * @param {string} content The content will show in error popup
    */
-  initErrorPopup(content) {
-    const typePopup = TYPE_POPUP.error;
-    const title = 'Error';
-    const btnContent = 'Got it!';
+  initErrorPopup(error) {
+    const title = error.title ? error.title : MESSAGE.DEFAULT_TITLE_ERROR_POPUP;
+    const content = error.message ? error.message : error;
 
-    this.initPopupContent(typePopup, title, content, btnContent);
+    this.initPopupContent(TYPE_POPUP.error, title, content, BTN_CONTENT.OK);
 
     // Show popup
     this.tooglePopupForm();
@@ -84,7 +85,7 @@ export default class RegisterView extends CommonLoginRegisterView {
         // Check user exist
         const userExist = await checkExistUser(user.email);
         if (userExist) {
-          throw Error('User is exists! Please try another email!');
+          throw Error(MESSAGE.USER_EXIST_ERROR);
         } else {
           await saveUser(user);
           // Show popup success
@@ -101,6 +102,6 @@ export default class RegisterView extends CommonLoginRegisterView {
   }
 
   isRegisterPage() {
-    return this.registerPage !== null;
+    return this.registerPage;
   }
 }
diff --git a/javascript-practice/src/pages/login.html b/javascript-practice/src/pages/login.html
index c502e11..bef7925 100644
--- a/javascript-practice/src/pages/login.html
+++ b/javascript-practice/src/pages/login.html
@@ -7,7 +7,7 @@
     <title>Login - Money Lover</title>
   </head>
   <body>
-    <main id="loginPage">
+    <main>
       <div class="background">
         <div class="wrapper">
           <img
diff --git a/javascript-practice/src/pages/register.html b/javascript-practice/src/pages/register.html
index bc28c70..f384cbf 100644
--- a/javascript-practice/src/pages/register.html
+++ b/javascript-practice/src/pages/register.html
@@ -7,7 +7,7 @@
     <title>Register - Money Lover</title>
   </head>
   <body>
-    <main id="registerPage">
+    <main>
       <div class="background">
         <div class="wrapper">
           <img