ezSQL and AJAX, anyone knows a good AJAX framework/toolkit ?

Hi,

I'm looking for an easy way to get started with AJAX, mainly for frontend user interfaces (e.g. chained comboboxes). For retrieving data from the database I would use ezSQL, of course.

Does anyone have experience with this? I'm looking for a good open source AJAX library that's easy to use. Does anyone know of such a library?

Thanks!