Sajax is a simple toolkit to expose functions in
your PHP scripts as JavaScript stubs which can be
called by the browser to do work on the server
without refreshing the page. It utilizes
XMLHttpRequest to make the magic happen. This kind
of technology, generally known as remote scripting
or "Ajax," is becoming popular and is used
extensively by Google (GMail, Google Suggests,
Google Maps) and others to provide another level
of interactivity within Web pages.