JQuery Ajax

Hey guys,
I want to keep my website constantly updated with data from a database.

I want to use JQuery for one user to send data to a php script to populate a mysql database but I also want other users to see this change clientside in real time. I know that JQuery can greatly simplify AJAX functionality but I need a rough guideline of what to do. I am an ok PHP developer and have used JQuery quite a lot so should be ok with that side of things, its just which AJAX functions to use,

jquery is easy to show something for client,if you associal database,you better to use XAJAX for php.it’s an open source code,and so easy to use…

OK thanks, I’ll check it out.