在渲染布局时，如何让Rails排除application.erb？

I'm making an AAJX request to an action in a controller. I fetch the rendered HTML and display it in a tag in the current page. The view that I'm POSTing to, renders the layout with the default application.erb. I would like rails to use the default layout for the controller/action but not render the main application.erb. How do I do this?I'm making an AAJX request to an action in a co