Load the content of a CallbackPanel inside a container (div, span, table cell, etc.).
For example, you can use the next lines:
Client-side update
ob_post.UpdatePanelInContainer("callbackPanel1", "container");
Server-side update
UpdatePanel("callbackPanel1", "container");
<oajax:CallbackPanel runat="server" ID="callbackPanel1">
<content style="border: gray 1px solid;">
...
callback panel content
...
</content>
</oajax:CallbackPanel>
<div id="container" style="border:1px solid red" />
See also live
UpdatePanelInContainer Example.
For more information about CallbackPanel see
How It Works page.