<?php
                if(isset($_POST['btnLogin'])){
                    $username = $_POST['txtUsername'];
                    $password = $_POST['txtPassword'];

                    $u = new User(-1, 0, time(), $username, $password, '', '', '', 0, 0);
                    if($u->Login() == true)
                    {
                        echo 'ok'; //Response to Ajax
                        $_SESSION["IsLogin"] = 1; // Login Success
                        $_SESSION["CurrentUser"] = (array)$u;
                    }
                    else
                    {
                        echo '<div class="alert alert-danger">Wrong Username or Password</div>';
                    }
                }
                    ?>

jQuery(function($) {
     /* validation */
  $("#login-form").validate({
      rules:
   {
   txtUsername: {
   required: true,
   },
   txtPassword: {
            required: true,
            },
    },
    submitHandler: submitForm
       });
    /* validation */

    /* login submit */
    function submitForm()
    {
   var data = $("#login-form").serialize();

   $.ajax({

   type : 'POST',
   url  : 'http://gtazombie.net/dangnhap.php',
   data : data,
   beforeSend: function()
   {
    $("#error").fadeOut();
    $("#error").html('<div class="alert alert-info"><center><i class="fa fa-refresh fa-spin fa-3x"></i></br><p>Loging</p></center></div>');
   },
   success :  function(response)
      {
     if(response == 'ok'){
      $("#error").html('<div class="alert alert-success"><i class="fa fa-refresh fa-spin fa-3x fa-fw margin-bottom"></i>SUCCESS</div>');
      setTimeout(' window.location.href = "thongtin.php"; ',3000);
     }
     else{
      $("#error").fadeIn(1000, function(){
        $("#error").html('<div class="alert alert-danger">Wrong Username or Password</div>');
         });
     }
     }
   });
    return false;
  }
    /* login submit */
});