login.php

<?php
session_start(); // memulai session
include "koneksi.php"; //panggil file koneksi.php
?>
<form action="" method="POST">
<table>
<tr><td>Username</td><td>:</td><td><input type="text" name="username" value=""></td><tr>
<tr><td>Password</td><td>:</td><td><input type="password" name="password" value=""></td><tr>
<tr><td colspan="2"></td><td><input type="submit" name="login" value="Login"></td><tr>
</table>
</form>

<?php
if(isset($_POST['login'])){ // kondisi if jika $_POST['login'] memiliki nilai
    $query=mysql_query("select * from user where username='$_POST[username]' and password='$_POST[password]'"); //Query database
    $rows = mysql_num_rows($query); //memerikasa apakah ada data
    if($rows>0){ // kondisi if untuk memeriksa data login
        $data=mysql_fetch_array($query); //membuat data hasil query dalam bentuk array
        $_SESSION['username']=$data['username']; //simpan data username kedalam variable $_SESSION['username']
        $_SESSION['password']=$data['password']; //simpan data password kedalam variable $_SESSION['password']
        $_SESSION['nama']=$data['nama']; //simpan data password kedalam variable $_SESSION['password']
        $_SESSION['level']=$data['level']; //simpan data level kedalam variable $_SESSION['level']
        if($_SESSION['level']=='admin'){ // kondisi if jika nilai dari $_SESSION['level'] sama dengan admin
            echo "<script>alert('Login Suksek'); window.location='halaman_admin.php';</script>"; //menampilkan pesan sukses dan redirect halaman
        }else if($_SESSION['level']=='petugas'){ // kondisi if jika nilai dari $_SESSION['level'] sama dengan petugas
            echo "<script>alert('Login sukses'); window.location='halaman_petugas.php';</script>"; //menampilkan pesan sukses dan redirect halaman
        }
    }else{
        echo "<script>alert('Gagal Login'); window.location='login.php';</script>"; //menampilkan pesan sukses dan redirect halaman
    }
}
?>