title: jQuery datatables add class to tr
body: <p>I am using jQuery and datatables.  I want to add a class to the TR element of a particular row.  I know how to find the row. The <code>console.dir(row);</code> shows the <code>row</code> object and that starts with a <code>tr</code> element.  I can't get the jQuery selector to do anything though.  What am I missing?</p>
  
  <pre><code>table = $('#resultTable').DataTable({
      aaSorting: [],
      ajax: {...},
      columnDefs: [...],
      createdRow: function (row, data, index) {
          //
          // if the second column cell is blank apply special formatting
          //
          if (data[1] == "") {
              console.dir(row);
              $('tr', row).addClass('label-warning');
          }
      }
  });
  </code></pre>