title: PHP booking reference validation not working
body: <p>"For a reference to be valid, the three letter group must be one of ‘ACT’, ‘ABQ’, ‘ ‘BDE’. Anything else is invalid."</p>
  
  <p>My code is below but it doesn't seem to be working as intended. Could somebody please point me in the right direction. Thanks.</p>
  
  <pre><code>if (isset($webdata['bookingreference'] )) {
      if (!preg_match("[ABQ,ACT,BDE]{1}[-]{1}[1-2]{1}[0-9]{3}", $webdata['bookingreference'])) {
          $formerror['bookingreference'] = '&lt;span class="warn" &gt;Not valid on server: The ref must start with ABQ, ACT or BDE, followed by a hyphen, then either the numbers 1 or 2 followed by two more numbers 0-9';
          $valid = FALSE;
  </code></pre>