//ini script cek_login.php
<?php
session_start();

include"../config/koneksi2.php";

$u=mysqli_query($conn, "SELECT * FROM admin WHERE user_name ='".$_POST['username']."' AND password='".md5($_POST['pwd'])."'");
$jml=mysqli_num_rows($u);
 if($jml == 1){
 	header('Location: admin.php');
 	$_SESSION['username'] = $_POST['username'];
 }else{
 	echo "gagal";
 }

?>

//ini script koneksi2.php

<?php
$servername = "localhost";
$database = "db_sipil";
$username = "root";
$password = "";

$conn = mysqli_connect($servername, $username, $password, $database);
// mengecek koneksi

?>