Form Validation through JQUERY

[eluser]Caelis[/eluser]
I have a couple of questions:
What is best practice, use CodeIgniters Validation Class for form validation or use something like http://plugins.jquery.com/project/RSV ?

Also, is it possible to use CodeIgniters Validation Class in an AJAX kind of way?

For now, I've been using CodeIgniters Validation Class in my small application,
but I want instant validation when a user enters values in a form instead of having to submit the form first.

Any help would be greatly appreciated.

Oh, and might I add that CodeIgniter is just amazing!
Never used any other php-framework before because they all seemed so bloated and difficult to learn, but CodeIgniter is really easy to learn and has helped me improve my programming a lot!