Cakephp-Send Multiple elements in ajax request frpm ajaxhelper/jshelper

From the following post

http://itfeast.blogspot.in/2013/06/cakephp-20-create-0bserve-field.html

To send multiple elements in ajax request from ajaxhelper/jshelper

 'data'=>$(\'#category,#sort\');  

For example this is how I passed the same in cakephp

  <script type="text/javascript">  
            <?php   
              echo $this->Js->get('#category')->event('change',$this->Js->request(  
                  array('controller' => 'contributors', 'action' => 'changevideos'),  
                  array('update'=>'#vediocontainer','async' => true,'dataExpression' => true,'method' => 'post','data'=>'$(\'#category,#sort,#fileid\').serializeArray()')  
                  ),false);  
             ?>