title: jQuery $.POST not working - Add a variable in $_SESSION
body: <p>I have a file named "test.php" with a link to "test2.php":</p>
  
  <pre><code>&lt;a href="test2.php" id="test"&gt;Test&lt;/a&gt;
  </code></pre>
  
  <p>In my test2.php, I check the $_SESSION variable:</p>
  
  <pre><code>&lt;?php session_start();
  var_dump($_SESSION);
  </code></pre>
  
  <p>When I click on the link in the "test.php" file, I want to add data in the $_SESSION variable, so here is my js: </p>
  
  <pre><code>$('#test').on('click', function(e) {
     $.post('test3.php', { myvar : 'myvalue' } );
  });
  </code></pre>
  
  <p>And on the "test3.php" file, I have this piece of code: </p>
  
  <pre><code>&lt;?php session_start();
      $_SESSION['myvar'] = $_POST['myvar'];
  </code></pre>
  
  <p>I don't understand why it's not working... In the "test2.php" file, the $_SESSION['myvar'] does not exist.</p>
  
  <p>Thanks for your help!</p>