title: if(isset($_POST['submit'])) doesn't work
body: <p>I know there are a lot of questions here with the same title and problem but I've checked all of my syntax and I really have no clue why this doesn't work anymore (some time ago, it did work).</p>
  
  <pre><code>&lt;?php
  include_once("../../database/db_connect.php");
  include '../../chromephp-master/ChromePhp.php';
  date_default_timezone_set('Europe/Amsterdam');
  
  session_start();
  
  ChromePhp::log('Start...');
  
  if(!isset($_SESSION['username']) &amp;&amp; !isset($_SESSION['password'])) {
  
      ChromePhp::log('Nothing in the SESSION.');
  
      if(isset($_POST['submit'])){
          ChromePhp::log('Lets have a look at the data...');
          (...)
          ChromePhp::log('Login successful!');
  
          header('Location: news.php');
      } else {
          ChromePhp::log('Empty form.');
      }
  
  } else {
      header('Location: news.php');
  }
  ?&gt;
  </code></pre>
  
  <p>My form looks as follows:</p>
  
  <pre><code>&lt;form method="post" action="site/users/login" &gt;
      &lt;input type="text" name="username" value="Gebruikersnaam" /&gt;&lt;br /&gt;&lt;br /&gt;
      &lt;input type="password" name="pwrd" value="Wachtwoord" /&gt;&lt;br /&gt;&lt;br /&gt;
      &lt;input type="submit" name="submit" value="&amp;nbsp;Log in&amp;nbsp;" /&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>The form is on the same page as the PHP code; I point the action to "site/users/login" because in the head of the HTML page, I set <code>&lt;base href="../../"&gt;</code>.</p>
  
  <p>When I submit the form, the page reloads and the log says "Start...", then "Nothing in the SESSION." and finally "Empty form.".</p>
  
  <p>What am I doing wrong? All help is appreciated!</p>
  
  <p><strong>EDIT:</strong> This is the content of my htaccess file:</p>
  
  <pre><code>RewriteEngine On
  RewriteCond %{REQUEST_FILENAME} !-f
  RewriteRule ^([^\.]+)$ $1.php [NC,L]
  </code></pre>