title: variables in $_GET superglobal
body: <p>I have this page of code. It handles my content. It works great:</p>
  
  <pre><code>&lt;?PHP
      $page = $_GET["page"];
      if (isset($_GET['page'])) {
          $filename = $page . '.php';
          if (file_exists($filename)) {
              include $filename;
          } else {
              echo "deze pagina bestaat niet";
          }
      } else {
          include 'user.php';
      }
   ?&gt;
  </code></pre>
  
  <p>Now i want to go a step further and include a variable after the ?page=something.php
  If i put &amp;ID=24 after it is says that the page does not exist. for instance:</p>
  
  <pre><code>echo "&lt;a href='?page=something.php&amp;ID=" .$row['ID'] . "'&gt;something&lt;/a&gt;"
  </code></pre>
  
  <p>I understand why it doesn't work but i don't see how to make it work.</p>