A.  AJAX needs JavaScript and XmlHttpRequest
Cont…
–3.  Combine data abstraction with progressive enhancement
•Build apps using standard server side technology and web site UI technology
•Data abstraction is used to ensure that functions on server side can be reused in AJAX
•Then progressively build JS and AJAX capabilities on top.
•Means the app will degrade gracefully when JS/XmlHttpRequest is not supported
“With a little bit of forethought, you can build an application that can be used by everybody whilst giving the majority an enhanced experience”