title: Find id of panel at active index accordian bootstrap
body: <p>If i want to retrieve index of active panel of the accordion in bootstrap i use the following.</p>
  
  <pre><code>var index = $('#accordion .in').parent().index();
  </code></pre>
  
  <p>How could retrieve the 'id' of this active panel?</p>
  
  <p>regards</p>