title: jquery sortable - gives empty array in response
body: <p>I am using jquery ui sortable for my codeigniter website but when i am sorting data it will give me empty array in console.
  please check and let me know my mistake.</p>
  
  <pre><code>    &lt;script&gt;
  $(document).ready( function() {
      $("#sortme tbody").sortable({
          update : function (event, ui) {
          //    console.log(ui);
          serial = $('#sortme tbody td .ds').sortable();
              console.log(serial);
  
              $.ajax({
                  url: "&lt;?=base_url().'admin/pages/save_order'?&gt;",
                  type: "post",
                  data: serial,
                  success: function(response,data){
                      console.log(response);
                  },
                  error: function(){
                      alert("theres an error with AJAX");
                  }
              });
           }
      });
  });
  &lt;/script&gt;  
  </code></pre>
  
  <p>here controller</p>
  
  <pre><code>public function save_order()
  {
      print_r($_POST);
      exit;
      $menu = $_POST['menu'];
      for ($i = 0; $i &lt; count($menu); $i++)
      {
      echo $menu[$i];
      }
  }
  </code></pre>