diff --git a/connection.php b/connection.php
index 37c9e4d..7d38394 100644
--- a/connection.php
+++ b/connection.php
@@ -1,32 +1,18 @@
 <?php
 
-/**
- * Class Db
- */
 class Db {
 
-    /**
-     * @var null
-     */
+
     private static $instance = NULL;
 
-    /**
-     * Db constructor.
-     */
     private function __construct() {}
 
-    /**
-     *
-     */
     private function __clone() {}
 
-    /**
-     * @return null|PDO
-     */
     public static function getInstance() {
       if (!isset(self::$instance)) {
         $pdo_options[PDO::ATTR_ERRMODE] = PDO::ERRMODE_EXCEPTION;
-        self::$instance = new PDO('mysql:host=localhost;dbname=post', 'post', 'post', $pdo_options);
+        self::$instance = new PDO('mysql:host=localhost;dbname=posts', 'root', '', $pdo_options);
       }
       return self::$instance;
     }
diff --git a/controllers/posts_controller.php b/controllers/posts_controller.php
index 8e2be0d..8724d15 100644
--- a/controllers/posts_controller.php
+++ b/controllers/posts_controller.php
@@ -27,5 +27,54 @@ public function show() {
       $post = Post::find($_GET['id']);
       require_once('views/posts/show.php');
     }
+
+      public function add()
+      {    
+          require_once('views/posts/add.php');
+      }
+      public function doAdd()
+      {
+        $first_name = $_POST['first_name'];
+        $last_name = $_POST['last_name'];
+        $author = $_POST['author'];
+        $content = $_POST['content'];
+        $arr  = array(
+          'first_name' => $first_name,
+          'last_name' => $last_name,
+          'author' => $author,
+          'content' => $content
+        );
+        $post = Post::add($arr);
+      }
+
+        public function delete()
+       {
+        if (isset($_POST['id']))
+          $post = Post::delete($_POST['id']);
+        require_once('views/posts/delete.php');
+        }
+
+         public function update()
+      {    
+          require_once('views/posts/update.php');
+      }
+      public function doUpdate()
+      {
+        if (isset($_POST['id']))
+         $id = $_POST['id'];
+         $first_name = $_POST['first_name'];
+         $last_name = $_POST['last_name'];
+         $author = $_POST['author'];
+         $content = $_POST['content'];
+         $arr  = array(
+          'id' => $id,
+          'first_name' => $first_name,
+          'last_name' => $last_name,
+          'author' => $author,
+          'content' => $content
+        );
+        $post = Post::update($array);
+      }
   }
+
 ?>
\ No newline at end of file
diff --git a/models/post.php b/models/post.php
index 5cd60b8..adbc1a4 100644
--- a/models/post.php
+++ b/models/post.php
@@ -1,23 +1,18 @@
 <?php
 
-/**
- * Class Post
- */
 class Post {
-    // we define 3 attributes
+    // we define 5 attributes
     // they are public so that we can access them using $post->author directly
     public $id;
+    public $first_name;
+    public $last_name;
     public $author;
     public $content;
+    public $created;
+    public $modified;
 
-    /**
-     * Post constructor.
-     * @param $id
-     * @param $author
-     * @param $content
-    */
     public function __construct($id, $author, $content) {
-      $this->id      = $id;
+      $this->id = $id;
       $this->author  = $author;
       $this->content = $content;
     }
@@ -53,5 +48,52 @@ public static function find($id) {
 
       return new Post($post['id'], $post['author'], $post['content']);
     }
-  }
+    public static function add($arr) {
+      $db = Db::getInstance();
+      $time = date("Y-m-d h:sa:i");
+      $sql = "INSERT INTO `posts` (`id`, `first_name`, `last_name`, `author`, `content`, `created`, `modified`) VALUES (NULL, '".$_POST['first_name']."', '".$_POST['last_name']."', '".$_POST['author']."', '".$_POST['content']."', '".$time."', '".$time."')";
+    
+      $query = $db->query($sql);
+      if($query)
+      {
+        echo "Successful!";
+      }
+      else {
+        echo "Error!";
+      }
+  } 
+
+    public static function delete($id) {
+      try
+      {
+       $db = Db::getInstance();
+       // we make sure $id is an integer
+       $id = intval($id);
+       $sql = "DELETE FROM `posts` WHERE id= $id";
+       $query = $db->exec($sql);
+       echo "Successful!";
+      }
+      catch(PDOException $e)
+    {
+    echo $query . "<br>" . $e->getMessage();
+    }
+    }
+
+     public static function update($array) {
+      try
+      {
+       $db = Db::getInstance();
+       // we make sure $id is an integer
+       $id = $_POST['id'];
+       $id = intval($id);
+       $sql = "UPDATE `posts` SET `first_name`='".$_POST['first_name']."','".`last_name`."'='".$_POST['last_name']."','".`author`."'='".$_POST['author']."','".`content`."'='".$_POST['content']."' WHERE id = $id ";
+       $query = $db->query($sql);
+        echo "Successful!";
+      }
+      catch(PDOException $e)
+    {
+    echo $query . "<br>" . $e->getMessage();
+    }
+      }
+    }
 ?>
\ No newline at end of file
diff --git a/post.sql b/post.sql
index 1a616aa..4302ccf 100644
--- a/post.sql
+++ b/post.sql
@@ -1,4 +1,3 @@
--------------------------------------------------------
 
 DROP TABLE IF EXISTS `posts`;
 
diff --git a/routes.php b/routes.php
index d0b5ab5..823603e 100644
--- a/routes.php
+++ b/routes.php
@@ -18,7 +18,7 @@ function call($controller, $action) {
 
   // we're adding an entry for the new controller and its actions
   $controllers = array('pages' => ['home', 'error'],
-                       'posts' => ['index', 'show']);
+                       'posts' => ['index', 'show', 'add','doAdd', 'delete', 'update', 'doUpdate']);
 
 /** @var string $controller */
 if (array_key_exists($controller, $controllers)) {
diff --git a/views/layout.php b/views/layout.php
index 279fb4f..c4fed09 100644
--- a/views/layout.php
+++ b/views/layout.php
@@ -4,8 +4,11 @@
   </head>
   <body>
     <header>
-      <a href='/php_mvc'>Home</a>
+      <a href='?controller=pages&action=home'>Home</a>
       <a href='?controller=posts&action=index'>Posts</a>
+      <a href='?controller=posts&action=add'>Add</a>
+      <a href='?controller=posts&action=delete'>Delete</a>
+      <a href='?controller=posts&action=update'>Update</a>
     </header>
 
     <?php require_once('routes.php'); ?>
diff --git a/views/posts/add.php b/views/posts/add.php
new file mode 100644
index 0000000..d4659f2
--- /dev/null
+++ b/views/posts/add.php
@@ -0,0 +1,28 @@
+<!DOCTYPE html>
+<html>
+<head>
+	<title>Them du lieu</title>
+</head>
+<body>
+    <br /> <br />
+<form action="?controller=posts&action=doAdd" method="post">
+	<table>
+    <tr>
+        <th> first_name:</th> 
+        <td> <input type="text" name="first_name" value=""> </td>
+    </tr>
+    <tr>
+        <th> last_name: </th> <td> <input type="text" name="last_name" value="" /> </td>
+    </tr>
+    <tr>
+        <th> author: </th> <td> <input type="text" name="author" value="" /> </td>
+    </tr>
+    <tr>
+        <th> content: </th> <td> <input type="text" name="content" value="" /> </td>
+    </tr>
+    
+    </table>
+    <input type="submit" name="submit" value="add">
+</form>
+</body>
+</html>
\ No newline at end of file
diff --git a/views/posts/delete.php b/views/posts/delete.php
new file mode 100644
index 0000000..87c3ecc
--- /dev/null
+++ b/views/posts/delete.php
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html>
+<head>
+	<title>Xoa du lieu</title>
+</head>
+<body>
+	<br /> <br />
+	<form action="?controller=posts&action=delete" method="post">
+	ID: <input type="text" name="id" value = "" />
+	<input type="submit" name="submit" value="delete">
+</body>
+</html>
\ No newline at end of file
diff --git a/views/posts/update.php b/views/posts/update.php
new file mode 100644
index 0000000..e913dca
--- /dev/null
+++ b/views/posts/update.php
@@ -0,0 +1,30 @@
+<!DOCTYPE html>
+<html>
+<head>
+	<title>Chinh sua du lieu</title>
+</head>
+<body>
+    <br /> <br />
+<form action="?controller=posts&action=update" method="post">
+	<table>
+    <tr>
+        <th> first_name:</th> 
+        <td> <input type="text" name="first_name" value=""> </td>
+    </tr>
+    <tr>
+        <th> last_name: </th> <td> <input type="text" name="last_name" value="" /> </td>
+    </tr>
+    <tr>
+        <th> author: </th> <td> <input type="text" name="author" value="" /> </td>
+    </tr>
+    <tr>
+        <th> content: </th> <td> <input type="text" name="content" value="" /> </td>
+    </tr>
+    
+    </table>
+    <br /> <br />
+    ID: <input type="text" name = "ID" value="">
+    <input type="submit" name="submit" value="update">
+</form>
+</body>
+</html>
\ No newline at end of file