How to learning Ajax ,you can mastered the base grammar of the Javascript,then you’ll see a simple example of AJAX.
A classic example of AJAX is Google Maps. If you havent noticed, with Google Maps you have the ability to click and drag the map. If you drag the map fast enough, you would see the new regions of the map loading in real-time. This is accomplished using AJAX.
there is a quick overview and example of AJAX in action
http://www.sematopia.com/2005/11/how...in-10-minutes/
http://www.thecoolad.com