AHAH (Asynchronous HTML and HTTP) is a method for updating webpages dynamically via JavaScript. It is similar to AJAX, except that the response from the request is used directly without any parsing on the client-side. This means that server responses need to be text or already include a valid XHTML / HTML structure themselves.
If you are not going to modify the content structure of the XMLHTTP response any further, then it is usually recommended to use AHAH due to it's ease of use, minimum complexity, and improved speed and readability. The innerHTML attribute is also widely supported, but being a Microsoft proprietary attribute, it is not part of the W3C DOM recommendations, and a lot of people stay away from it for that reason alone.
If changes to the response XHTML structure beyond any simple string operations are needed, a DOM-centric approach (such as with AJAX) is preferable - since references to elements based on the response contents (which have then been appended to the target element and have already been created) can then be reused. [more]
