Update scrollbar in success of ajax

[BDhara]

The code is like
$.ajax({
type: "POST",
url: '@Url.Action("testMethod")',
dataType: "json",
mtype: "post",
success: function (data) {
$("#sidebar").ace_scroll({ inline_style: true, size: 680, observeContent: true });
}
});

But it doesnot update after adding new li to sidebar..