config

<?php

class Auth
{

   public $con;

   function __construct()
   {
      $host = 'localhost';
      $user = 'root';
      $pass = '';
      $db   = 'logout';

      $this->con  = new mysqli($host, $user, $pass, $db) or die($con->error);
   }

   public function login($user = null, $pass = null) {

      $query = $this->con->prepare("SELECT * FROM `t_user` WHERE `username` = ? && `password` = MD5(?)");
      $query->bind_param('ss', $user, $pass);
      $query->execute();
      $query->store_result();
      $total = $query->num_rows();
      $query->bind_result($id, $user, $fullname,$password);
      $query->fetch();

      if ($total > 0)
      {
         //set_session
         $_SESSION['iduser']   = $id;
         $_SESSION['is_login'] = TRUE;

      } else {
         echo '<script type="text/javascript">alert("Akun tidak dikenali")</script>';
      }
   }

}