Untitled

Index.php

<!DOCTYPE html>
<html>
<head>
	<title>index.php</title>
	<link rel="stylesheet" type="text/css" href="style.css">
</head>
<body>
	<br/>
	<br/>
	<center><h2>bayu elsya</h2></center>
	<br/>
	<div class="login">
	<br/>
		<form action="login.php" method="post" onSubmit="return validasi()">
			<div>
				<label>Username:</label>
				<input type="text" name="username" id="username" />
			</div>
			<div>
				<label>Password:</label>
				<input type="password" name="password" id="password" />
			</div>
			<div>
				<input type="submit" value="Login" class="tombol">
			</div>
		</form>
	</div>
</body>

<script type="text/javascript">
	function validasi() {
		var username = document.getElementById("username").value;
		var password = document.getElementById("password").value;
		if (username != "" && password!="") {
			return true;
		}else{
			alert('Username dan Password harus di isi !');
			return false;
		}
	}

</script>
</html>

====
Login.php
<?php
include 'config.php';

$username = $_POST['username'];
$password = md5($_POST['password']);

$login = mysql_query("select * from user where username='$username' and password='$password'");
$cek = mysql_num_rows($login);

if($cek > 0){
	session_start();
	$_SESSION['username'] = $username;
	$_SESSION['status'] = "login";
	header("location:admin/index.php");
}else{
	header("location:index.php");
}

?>

======
Conffig.php

<?php
mysql_connect('localhost','root','');
mysql_select_db('admin');
?>

=====
/Admin/index.php

<?php
include '../config.php';

// mengaktifkan session
session_start();

// cek apakah user telah login, jika belum login maka di alihkan ke halaman login
if($_SESSION['status'] !="login"){
	header("location:../index.php");
}

// menampilkan pesan selamat datang
echo "Hai, selamat datang ". $_SESSION['username'];

?>
<br/>
<br/>
<a href="logout.php">LOGOUT</a>

=====
Logout.php
<?php
session_start();
session_destroy();
header("location:../index.php");
?>


=====
Tabel

CREATE TABLE `user` (
  `id` int(11) NOT NULL,
  `nama` varchar(225) NOT NULL,
  `username` varchar(225) NOT NULL,
  `password` varchar(225) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;