You cannot use AJAX if JavaScript is disabled.

Always try to write your code for non-JavaScript clients and then add AJAX afterwords.

AJAX should be used to enhance the page, it should not be the core of it.

Dangari,

I've not heard the term "degradable AJAX" and can only guess at what it might mean.

As Will G says, AJAX simply won't work at all if Javascript is turned off.

However, you may choose to cater for (rare?) browsers with low capability Javascript that doesn't support the HTTPRequest object necessary for AJAX. The strategy (I've never needed to use it) would be always to try making an AJAX request then, if AJAX fails, make a regualr HTTP request (with suitable GET or POST parameters) to reload the whole page (with necessary additions/modifications). You would generally choose to do this only for essential functionality - not some "fancy-waistcoats" visual effect.

Airshow

You might want to research "HIJAX" which is an approach (like "AJAX" neither a product nor a language).

HIJAX gets a mention (but no more than that) in one of my reference books - "Beginning Javascript with DOM Scripting and AJAX" by Christine Heilmann (Apress, 2006), ISBN 1-59059-680-3. Apparantly HIJAX was coined by a Jeremy Keith, so it may also be worth searching for publications that bear his name.

Sorry I can't be of any more help but, like many if not most AJAX programmers I suspect, I am guilty of having not handled failure cases as robustly as I could have. Your question is a prompt for me to learn more. You may look forward to answering my questions some time in the future!

Airshow