Ajax type applications allow developers to update parts of a web page without needing to refresh the entire page. Click on a link and another area of the screen is updated, click a toggle arrow to expand and collapse an inline detail box, submit a form and receive confirmation without updating the page, and so on.
This type of interaction uses asynchronous HTTP calls back to the server (to get data, or process form submissions, and so on) and client side JavaScript to update specific parts of a page (usually defined using

ColdFusion 8 makes this type of interaction very simple by allowing controls to be bound to other controls, so that when one control changes (or an event occurs) a second control may be updated by making an asynchronous call to ColdFusion on the server.
To demonstrate this, here is a simple example. A list of art items is displayed in a control) as an argument. This way, whenever the selection in the