$(function() {
    $("#sortable").sortable({
        update: function(e, ui) {
            //process each image  
            var ids = "";
            $("#sortable").find('li').each(function() {
                if (ids.toString() != "") ids += ",";
                ids += $(this).children(':first').html();
            });
            $("input[id$=lblIds]").val(ids);
        }
    });
    $("#sortable").disableSelection();
});