diff --git a/typescript-practice/src/ts/global/types.ts b/typescript-practice/src/ts/global/types.ts
index 7307404..51de0c4 100644
--- a/typescript-practice/src/ts/global/types.ts
+++ b/typescript-practice/src/ts/global/types.ts
@@ -1,4 +1,14 @@
-export interface DataObject {
+export interface IDataObject<T> {
   id: string;
-  data: object;
+  data: T;
+}
+
+export class DataObject<T> {
+  public id: string;
+  public data: T;
+
+  constructor(dataObject: IDataObject<T>) {
+    this.id = dataObject?.id ?? null;
+    this.data = dataObject.data;
+  }
 }
diff --git a/typescript-practice/src/ts/helpers/connect.ts b/typescript-practice/src/ts/helpers/connect.ts
new file mode 100644
index 0000000..724a999
--- /dev/null
+++ b/typescript-practice/src/ts/helpers/connect.ts
@@ -0,0 +1,33 @@
+import { TIME_OUT_ERROR } from '../constants/message';
+import { TIME_OUT_SEC } from '../constants/config';
+import FirebaseService from '../services/firebaseService';
+
+/**
+ * A waiting function with s second
+ * @param {number} s The time will be waiting
+ * @returns {Promise} A Promise will be only reject after s second
+ */
+export const timeout = (s: number): Promise<string> => {
+  return new Promise((_, reject) => {
+    setTimeout(() => {
+      FirebaseService.disconnect();
+      reject(TIME_OUT_ERROR);
+    }, s * 1000);
+  });
+};
+
+/**
+ * A function waiting the action need to be perform and throw error after s second.
+ * @param {Function} action The action need to be perform.
+ * @returns { Object || Error } Return the any object from Firebase or Error
+ */
+export const timeOutConnect = async <T>(
+  action: Promise<T>,
+): Promise<string | T> => {
+  const result: T | string = await Promise.race([
+    action,
+    timeout(TIME_OUT_SEC),
+  ]);
+
+  return result;
+};
diff --git a/typescript-practice/src/ts/helpers/data.ts b/typescript-practice/src/ts/helpers/data.ts
new file mode 100644
index 0000000..2f0ac13
--- /dev/null
+++ b/typescript-practice/src/ts/helpers/data.ts
@@ -0,0 +1,19 @@
+import { DataObject } from '../global/types';
+
+export const createIdUser = (): number => {
+  return new Date().getTime();
+};
+
+export const convertDataObjectToModel = <T>(dataObj: DataObject<T>): T => {
+  const { id } = dataObj;
+
+  return { id, ...dataObj.data } as T;
+};
+
+export const convertModelToDataObject = <T extends DataObject<T>>(
+  model: T,
+): T => {
+  const { id, ...data } = model;
+
+  return { id, data } as T;
+};
diff --git a/typescript-practice/src/ts/helpers/helpers.ts b/typescript-practice/src/ts/helpers/helpers.ts
deleted file mode 100644
index 26b62f5..0000000
--- a/typescript-practice/src/ts/helpers/helpers.ts
+++ /dev/null
@@ -1,85 +0,0 @@
-import * as MESSAGE from '../constants/message';
-import { TIME_OUT_SEC, REGEX } from '../constants/config';
-import FirebaseService from '../services/firebaseService';
-import { DataObject } from '../global/types';
-
-/**
- * Validate password
- * @param {string} password Password input
- * @returns {boolean} Return true if validate password success, otherwise return false
- */
-export const isValidPassword = (password: string): boolean => {
-  return REGEX.PASSWORD.test(password);
-};
-
-export const isValidateEmail = (email: string): RegExpMatchArray | null => {
-  return String(email).toLowerCase().match(REGEX.EMAIL);
-};
-
-export const compare2Password = (
-  password: string,
-  passwordConfirm: string,
-): boolean => {
-  return password === passwordConfirm;
-};
-
-/**
- * A waiting function with s second
- * @param {number} s The time will be waiting
- * @returns {Promise} A Promise will be only reject after s second
- */
-export const timeout = (s: number): Promise<string> => {
-  return new Promise((_, reject) => {
-    setTimeout(() => {
-      FirebaseService.disconnect();
-      reject(MESSAGE.TIME_OUT_ERROR);
-    }, s * 1000);
-  });
-};
-
-export const createIdUser = (): number => {
-  return new Date().getTime();
-};
-
-/**
- * A function waiting the action need to be perform and throw error after s second.
- * @param {Function} action The action need to be perform.
- * @returns { Object || Error } Return the any object from Firebase or Error
- */
-export const timeOutConnect = async <T>(
-  action: Promise<T>,
-): Promise<string | T> => {
-  const result: T | string = await Promise.race([
-    action,
-    timeout(TIME_OUT_SEC),
-  ]);
-
-  return result;
-};
-
-export const renderRequiredText = (field: string, element: Element): void => {
-  const markup: string = `
-    <p class="error-text">${MESSAGE.REQUIRED_MESSAGE(field)}</p>
-  `;
-
-  element.insertAdjacentHTML('afterend', markup);
-};
-
-export const redirectToLoginPage = (): void => {
-  window.location.replace('/login');
-};
-
-export const convertDataObjectToModel = (dataObj: {
-  id: string;
-  data: object;
-}): DataObject => {
-  const { id } = dataObj;
-
-  return { id, ...dataObj.data } as DataObject;
-};
-
-export const convertModelToDataObject = <T extends DataObject>(model: T): T => {
-  const { id, ...data } = model;
-
-  return { id, data } as T;
-};
diff --git a/typescript-practice/src/ts/helpers/redirect.ts b/typescript-practice/src/ts/helpers/redirect.ts
new file mode 100644
index 0000000..e19d01c
--- /dev/null
+++ b/typescript-practice/src/ts/helpers/redirect.ts
@@ -0,0 +1,3 @@
+export const redirectToLoginPage = (): void => {
+  window.location.replace('/login');
+};
diff --git a/typescript-practice/src/ts/helpers/validatorForm.ts b/typescript-practice/src/ts/helpers/validatorForm.ts
new file mode 100644
index 0000000..f5d9326
--- /dev/null
+++ b/typescript-practice/src/ts/helpers/validatorForm.ts
@@ -0,0 +1,30 @@
+import { REGEX } from '../constants/config';
+import * as MESSAGE from '../constants/message';
+
+/**
+ * Validate password
+ * @param {string} password Password input
+ * @returns {boolean} Return true if validate password success, otherwise return false
+ */
+export const isValidPassword = (password: string): boolean => {
+  return REGEX.PASSWORD.test(password);
+};
+
+export const isValidateEmail = (email: string): RegExpMatchArray | null => {
+  return String(email).toLowerCase().match(REGEX.EMAIL);
+};
+
+export const compare2Password = (
+  password: string,
+  passwordConfirm: string,
+): boolean => {
+  return password === passwordConfirm;
+};
+
+export const renderRequiredText = (field: string, element: Element): void => {
+  const markup: string = `
+    <p class="error-text">${MESSAGE.REQUIRED_MESSAGE(field)}</p>
+  `;
+
+  element.insertAdjacentHTML('afterend', markup);
+};
diff --git a/typescript-practice/src/ts/models/user.ts b/typescript-practice/src/ts/models/user.ts
index f4129a6..03ff9b8 100644
--- a/typescript-practice/src/ts/models/user.ts
+++ b/typescript-practice/src/ts/models/user.ts
@@ -1,4 +1,4 @@
-import { createIdUser } from '../helpers/helpers';
+import { createIdUser } from '../helpers/data';
 
 export default class User {
   private id: number;
diff --git a/typescript-practice/src/ts/services/commonService.ts b/typescript-practice/src/ts/services/commonService.ts
index 69c70c2..92f39cd 100644
--- a/typescript-practice/src/ts/services/commonService.ts
+++ b/typescript-practice/src/ts/services/commonService.ts
@@ -1,12 +1,12 @@
+import { timeOutConnect } from '../helpers/connect';
 import {
-  timeOutConnect,
   convertDataObjectToModel,
   convertModelToDataObject,
-} from '../helpers/helpers';
+} from '../helpers/data';
 import { DataObject } from '../global/types';
 import FirebaseService from './firebaseService';
 
-export default class CommonService<T extends DataObject> {
+export default class CommonService<T extends DataObject<T>> {
   private defaultPath: string = '/';
   private firebaseService = FirebaseService;
 
@@ -65,7 +65,7 @@ export default class CommonService<T extends DataObject> {
     if (typeof results === 'object') {
       // Convert format object
       return results.map((data) => {
-        const tempData = data as DataObject;
+        const tempData = data as DataObject<T>;
 
         return convertDataObjectToModel(tempData);
       });
@@ -89,7 +89,7 @@ export default class CommonService<T extends DataObject> {
       // Convert format object
 
       return results.map((data) => {
-        const tempData = data as DataObject;
+        const tempData = data as DataObject<T>;
 
         return convertDataObjectToModel(tempData);
       });