Cek Login

<?php
session_start();
include "koneksi.php";

if(isset($_POST['username']) && ($_POST['password'])){
     $admin_name = $db->real_escape_string($_POST['username']);
     $admin_password = $db->real_escape_string(md5($_POST['password']));
     $sql = "select * from tbl_admin where admin_username = '$admin_name' AND admin_password = '$admin_password'";
     $result = $db->query($sql) or die('Terjadi Kesalahan : '.$db->error);

    if ($result->num_rows == 1){
          $row = $result->fetch_assoc();

          $_SESSION['admin_name'] = $row['admin_name'];
          $_SESSION['admin_nama'] = $row['admin_nama'];
          $_SESSION['admin_level'] = $row['admin_level'];
          $_SESSION['admin_id'] = $row['admin_id'];
          header("location:../index.php");
          $_SESSION['pesan'] = '<p><div class="alert alert-success">Selamat datang <b>'.$_SESSION['admin_nama'].'</b></div></p>';

    }else{
          echo "<script>alert('Maaf, usrename atau password salah..');location.href='../login.php'</script>";
    }
}else{
     echo "<script>alert('Maaf, usrename atau password salah..');location.href='../login.php'</script>";
}
?>