PHP script won't run
<p>I'm currently coding a CMS in PHP in order to get back into PHP (I use to use it all the time). However, for some odd reason, when "including" or "requiring" my classes file,  it simply stops the php script, my login form (login.php's html) does not show up (whether I am logged in or not). Any help? Here are two of my scripts: </p>

<p>login.php:</p>

<pre><code>&lt;?php
session_start();
include "classes.php";
if(isset($_GET['logout'])) {
    setupSession(2); 
}
if($_SESSION['status'] == "online") header("location: admin.php");
if($_POST &amp;&amp; isset($_POST['username']) &amp;&amp; isset($_POST['password'])) {
    $un = $_POST['username'];
    $pwd = $_POST['password'];

    $mysql = new mySql();
    $mysql-&gt;validateUser($un, $pwd);
} else $attempt = 2;

?&gt;  
&lt;html&gt;
&lt;head&gt;
    &lt;title&gt;Log In&lt;/title&gt;
&lt;/head&gt;
&lt;body&gt;
&lt;form method="post" action=""&gt;
    &lt;label for="username"&gt;username: &lt;/label&gt;
    &lt;input type="text" name="username" /&gt;

    &lt;label for="password"&gt;password: &lt;/label&gt;
    &lt;input type="password" name="password" /&gt;

    &lt;input type="submit" value="Log In" name="submit" /&gt;
&lt;/form&gt;
&lt;/body&gt;
&lt;/html&gt;
</code></pre>

<p>and classes.php</p>

<pre><code>&lt;?php

class mySql {

    protected $dbname;
    protected $dbuser;
    protected $dbpass;
    protected $db;
    private $conn;

    function __construct() {
        $conn = new mysqli($dbname, $dbuser, $dbpass, $db);
    }

    public function validateUser($username, $password) {
        $query = "SELECT * FROM users WHERE username = ? AND password = ? LIMIT 1";

        if($stmt = $this-&gt;conn-&gt;prepare($query)) {
            $stmt-&gt;bind_param('ss', $username, $password);
            $stmt-&gt;execute();

            if($stmt-&gt;fetch()) {
                $stmt-&gt;close();
                setupSession(1);
            } else $attempt = 1;
        }
    }
}

function setupSession($status) {
    switch($status) {
        case 1:
            $_SESSION['status'] = "online";
            //other user variables
            header("location: admin.php");
            break;
        case 2:
            unset($_SESSION['status']);
            if(isset($_COOKIE[session_name()])) {
                setcookie(session_name(), '', time() - 1000);
            }
            session_destroy();
            break;
        default:
            session_start();
            if($_SESSION['status'] != "online") header("location: login.php");
            break;
    }
}

?&gt;  
</code></pre>
