login.php

<?php
session_start();
$error='';
if (isset($_POST['submit'])) {
    if (empty($_POST['username']) || empty($_POST['password'])) {
            $error = "Username atau Password Salah";
    }
    else
    {
            $username=$_POST['username'];
            $password=$_POST['password'];

            $connection = mysql_connect("localhost", "root", "12345");

            $username = stripcslashes($username);
            $password = stripcslashes($password);
            $username = mysql_real_escape_string($username);
            $password = mysql_real_escape_string($password);

            $db = mysql_select_db("db_ahp_buku", $connection);

            $query = mysql_query("select * from login where password='$password' AND username='$username'", $connection);
            $rows = mysql_num_rows($query);
            $r=mysql_fetch_array($query);

                if ($rows == 1) {
                        $_SESSION['login_user']=$username;
                        $_SESSION['tipe'] = $r['tipe'];

                    if($_SESSION['tipe'] == "admin") {

                            echo ("<SCRIPT LANGUAGE='JavaScript'>
                                window.alert('Selamat datang Admin')
                                window.location.href='home.php';
                                </SCRIPT>");
                        //header("location: home.php");
                    }
                    else if ($_SESSION['tipe'] == "user") {
                            echo ("<SCRIPT LANGUAGE='JavaScript'>
                                window.alert('Login Berhasil')
                                window.location.href='home.php';
                                </SCRIPT>");

                    }

                }
                else
                {
                        $error = "<script type='text/javascript'> alert('Username or Password is invalid'); </script>";
                        }
                        mysql_close($connection);
}
}
?>