hi,
actually i didnt understand your question completely.I think you want to update a particular control using ajax..
<br />
<% using (Ajax.BeginForm(new AjaxOptions()<br />
{<br />
UpdateTargetId = "UpdatingDiv",<br />
InsertionMode = InsertionMode.Replace,<br />
HttpMethod = "POST"<br />
}))<br />
{%<br />
<br />
and just place your control in that UpdatingDiv
Hope this may help you