title: update a single database field in cakephp - SHOULD BE SIMPLE
body: <p>Hey guys, I'm trying to create a 'booking confirmed' link, that when clicked changes the table field 'confirmed' from 0 to 1.</p>
  
  <p>so far I've got:</p>
  
  <pre><code>function admin_markAsConfirmed($id = null) {
      $this - &gt; Booking - &gt; id = $id;
      if ($this - &gt; Booking - &gt; saveField('confirmed', 1)) {
          $this - &gt; Session - &gt; setFlash('Booking Confirmed');
          $this - &gt; redirect(array('action' = &gt; 'admin_index'));
      }
  }
  </code></pre>
  
  <p>But it's not working. All this does is insert a new row, instead of editing the row specified by $id. </p>
  
  <p>How do I make this work? It seems so simple but I've been stuck for a good few hours on this.</p>