title: jQuery - unrecognized expression: :nth-child
body: <p>I am trying to select <code>:nth-child</code> using jquery, but it show syntax error.</p>
  
  <pre><code>Error: Syntax error, unrecognized expression: :nth-child
  </code></pre>
  
  <p><strong>Here is my code</strong></p>
  
  <pre><code>var i;
  jQuery('#' + id + ' .tab-pane').each(function (id, t) {
      var n = jQuery(this).attr('id', 'pane-' + t);
      var p_id = n.attr('id');
      jQuery('#' + id + ' .nav-tabs li:nth-child(' + i + ') a').attr('href', p_id);
      i++;
  });
  </code></pre>
  
  <p>please check my code what is missing here</p>