aksi_login

<?php
$username= $_POST['user'];
$password=$_POST['pass'];
$DB_NAME = 'kampus';
$DB_HOST = 'localhost';
$DB_USER = 'root';
$DB_PASS = '';
$mysqli = new mysqli($DB_HOST, $DB_USER, $DB_PASS, $DB_NAME);
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
$query = "SELECT * FROM admin WHERE user='$username' and pass = Md5('$password')";
$result = $mysqli->query($query) or die($mysqli->error.__LINE__);
if($result->num_rows > 0) {
    ?><script type="text/javascript">alert('Selamat Datang Admin');window.location.href="index.php";</script><?php
}
else {
    header("location:../index.php?pesan=gagal")or die(mysql_error());
}
?>