I found this interesting little "cross browser tool kit" online...it's pretty interesting.
The website says:
Newcomers to Ajax may be looking for an easy way to get up and running with some basic Ajax behaviours in a minimal amount of time. A good option for rapid prototyping of some basic Ajax form behaviours is to use AJFORM. AJFORM is an extremely lightweight and simple cross browser toolkit. It returns the result to a specified JavaScript function or variable. The most interesting thing about AJFORM is it degrades gracefully if the browser won`t support it. In this case, the form is submitted normally with a full page refresh.
AJFORM is a good tool for beginners to provide some basic ajax form capabilities, but is mainly for really simple apps.