public function login_student()
 {
     if (isset($_POST['username_stu']) && isset($_POST[tpl_students::password() . '_stu'])) {
         $username = $_POST[tpl_students::username() . '_stu'];
         $password = $_POST[tpl_students::password() . '_stu'];
         if (!empty($username) && !empty($password)) {
             $db = new data_base(tpl_students::students(), array(tpl_students::id(), tpl_students::first_name()), array(tpl_students::username() => $username, tpl_students::password() => $this->hash_password($password), tpl_students::status() => 1));
             $data = $db->get_where();
             if (!empty($data)) {
                 $session = new session_students();
                 $session->new_login_students();
                 $session->set_id_user($data[0][tpl_students::id()]);
                 if ($session->get_login_students()) {
                     echo json_encode(array('valid' => true, 'title' => 'Welcome !!', 'massage' => $data[0][tpl_students::first_name()]));
                 } else {
                     echo json_encode(array('valid' => false, 'title' => 'Oops !!', 'massage' => 'Was not username & password, please try again'));
                 }
             } else {
                 echo json_encode(array('valid' => false, 'title' => 'Oops !!', 'massage' => 'Was not username & password, please try again'));
             }
         } else {
             echo json_encode(array('valid' => false, 'title' => 'Oops !!', 'massage' => 'Was not username & password, please try again'));
         }
     } else {
         echo json_encode(array('valid' => false, 'title' => 'Oops !!', 'massage' => 'Was not username & password, please try again'));
     }
 }
"
                               name="<?php 
echo tpl_students::students() . '_' . tpl_students::last_name();
?>
"/>
                    </div>

                    <div class="form-group">
                        <label for=""> Username : </label>
                        <input type="text" class="form-control"
                               id="<?php 
echo tpl_students::students() . '_' . tpl_students::username();
?>
"
                               name="<?php 
echo tpl_students::students() . '_' . tpl_students::username();
?>
"/>
                    </div>

                    <div class="form-group">
                        <label for=""> Email : </label>
                        <input type="text" class="form-control"
                               id="<?php 
echo tpl_students::students() . '_' . tpl_students::email();
?>
"
                               name="<?php 
echo tpl_students::students() . '_' . tpl_students::email();
?>
"/>