I'm implementing sortable plugin of jQuery UI. There are two columns and we can drag and drop an element from one column to another column. I have the following javascript code:
$(function () {
     $("#sortable1, #sortable2").sortable({
         connectWith: ".connectedSortable",
         update: function () {
             var order1 = $('#sortable1').sortable('toArray').toString();
             var order2 = $('#sortable2').sortable('toArray').toString();
             alert("Order 1:" + order1 + "\n Order 2:" + order2); 
             $.ajax({
                 type: "POST",
                 url: "/echo/json/",
                 data: "order1=" + order1 + "&order2=" + order2,
                 dataType: "json",
                 success: function (data) {
                 }
             });
         }
     }).disableSelection();
 });
And HTML:
<ul id="sortable1" class="connectedSortable">
  <li class="ui-state-default" id='item1'>Item 1</li>
  <li class="ui-state-default" id='item2'>Item 2</li>
  <li class="ui-state-default" id='item3'>Item 3</li>
  <li class="ui-state-default" id='item4'>Item 4</li>
  <li class="ui-state-default" id='item5'>Item 5</li>
</ul>
 
<ul id="sortable2" class="connectedSortable">
  <li class="ui-state-highlight" id='item6'>Item 6</li>
  <li class="ui-state-highlight" id='item7'>Item 7</li>
  <li class="ui-state-highlight" id='item8'>Item 8</li>
  <li class="ui-state-highlight" id='item9'>Item 9</li>
  <li class="ui-state-highlight" id='item10'>Item 10</li>
</ul>
From above javascript, I can get the order of column 1 and column 2 after change as a whole. However, I would like to know the individual item that has been changed. Like, in this image below, I have Item3 dragged from Column 1 to Column 2. I want to get output like - Item3_before=Column1,Item3_after=Column2. 
In the javascript code above, by using start event like the update event, we can get the Before status of the elements, but not the individual element; it gives before status of all elements.