title: Can't delete php set cookie
body: <p>I've set a cookie through this call in php</p>
  
  <pre><code>setcookie('alert_msg', 'you have the add badge');
  </code></pre>
  
  <p>I have tried unsetting it this way</p>
  
  <pre><code>setcookie('alert_msg', '');
  setcookie('alert_msg', false);
  setcookie('alert_msg', false, 1);
  setcookie('alert_msg', false, time()-3600);
  setcookie('alert_msg', '', 1, '/');
  </code></pre>
  
  <p>and it still won't unset the cookie value in $_COOKIE['alert_msg'].</p>
  
  <p>I have tried in both Firefox and Chrome</p>
  
  <p>Code sample:</p>
  
  <pre><code>if (isset($_COOKIE['alert_msg'])) {
      $this-&gt;set('alert_msg', $_COOKIE['alert_msg']);
      unset($_COOKIE['alert_msg']);
      setcookie('alert_msg', '', 1, '/');
  }
  </code></pre>