title: dataTables jquery - how to add sorting image/icon?
body: <p>I use dataTables jquery. I want to  add sorting image to the columns and the image shd also change on sorting.That is, if the image is showing descending icon and on clicking it should change to ascending icon. How it can be done using dataTables jquery?</p>
  
  <p>My code:</p>
  
  <pre><code>$("#rates").dataTable({
           "bPaginate": false,
           "sScrollY":  "250px",
           "bAutoWidth": false,
           "bScrollCollapse": true,
           "fnInitComplete": function() {
                  this.css("visibility", "visible");},
                  "bLengthChange": false
      });
  </code></pre>