===index.php===
<?php include 'core/init.php'; ?>
<?php include 'includes/header.php'; ?>

<h1>Home</h1>
<p>Just a template.</p>

<?php include 'includes/aside.php'; ?>
<?php include 'includes/footer.php'; ?>


===includes/aside.php===
<aside>
<?php include 'includes/widgets/login.php'; ?>
</aside>

===includes/widgets/login.php===
<div class="widget">
		<h2>Login/Register</h2>
			<div class="inner">
			<form action="login.php" method="post">
			<ul id="login">
				<li>Username:<br><input type="text" name="username"></li>
				<li>Password:<br><input type="password" name="password"></li>
				<li><input type="submit" value="Log in"></li>
				<li><a href="register.php">Register</a></li>
			</ul>
		</form>
	</div>
</div>

===login.php===
<?php
include 'core/init.php';

if (user_exists('leroy') === true) {
	echo 'exists';
}
die();

if (empty($_POST) === false) {
	$username = $_POST['username'];
	$password = $_POST['password'];

	if (empty($username) === true || empty($password) === true) {
		$errors[] = 'You need to enter a username and password';
	} else if (user_exists($username) === false) {
		$errors[] = 'We can\'t find that username. Have you registered?';
	}
}


?>

===core/functions/general.php===
<?php
function sanitize($data) {
	return mysql_real_escape_string($data);
}
?>

===core/functions/users.php===
<?php
function user_exists($username) {
	$username = sanitize($username);
	return (mysql_result(mysql_query("SELECT COUNT(`user_id`) FROM `users` WHERE `username` = '$username'"), 0) == 1) ? true : false;
}
?>

===core/init.php===
<?php
session_start();
error_reporting(0);

require 'database/connect.php';
require 'functions/general.php';
require 'functions/users.php';

$errors = array();
?>

===core/database/connect.php===
<?php
$connect_error = 'Sorry, we\'re experiencing connection issues.';
mysql_connect('localhost', 'adultaus_a', 'pass123');
mysql_select_db('adultaus_up') or die($connect_error);
?>