title: Compare values of 2 sessions displaying blank page
body: <p>I am trying to check whether either condition exists and if it al does then perform an action. However, what is happening is that the page is producing no errors just white page. There is nothing in the <code>php_error.log</code> or Apache so obviously my markup is incorrect. Here is a brief outline of what I am trying to achieve.</p>
  
  <p>Firstly check that the user is logged in. If not then go to the header location.</p>
  
  <p>Secondly check that the user is at the correct level to view the page. If not then send them to the header location.</p>
  
  <p>Thirdly if both user is logged in and they have the correct level, (0 or 2) they can then view the page. If I remove the second if statement it works fine.</p>
  
  <pre><code>&lt;?php
  if(!isset($_SESSION['ls_logged_usr']) {
  header('Location: /mobile/index.php?error=NOLOGIN');
  exit;
  }
  ?&gt;
  &lt;?php
  if($_SESSION['ls_level_usr'] !== '0' || ($_SESSION['ls_level_usr'] !== '2') {
  header('Location: /mobile/index.php?error=LEVELERROR');
  exit;
  }
  //echo 'level: ' . $_SESSION['ls_level_usr'] . '&lt;br /&gt;' . 'Active: ' . $_SESSION['ls_active_usr'];
  
  ?&gt;
  </code></pre>