Using AJAX and XMLHttpRequest
If you're new here, you may want to subscribe to my RSS feed. Thanks for visiting!
Here is another good example of AJAX in action. With a very detailed walk thru on creating an AJAX form using Zip Codes as a demonstration.
Bill Bercik does an excellent job of sharing each piece of the puzzle with his audience. As with all AJAX tutorials some basic PHP, MySQL and JavaScript experience is needed. If you just want a good understanding of how the XMLHttpRequest works you can work through the first 4 steps. However, if you are familiar with MySQL and PHP the remaining steps are very helpful in pulling the whole process together.
Link : Guide to Using AJAX and XMLHttpRequest from WebPasties