I've found this tutorial  http://www.youtube.com/watch?v=8wUu7pWBygY, that basically does what i want, but, i have a problem... this is nice for a single field validation, but, for example, if it was a registration form, with multiple fields for validation: new login, check if exists in DB or not, email, check if exists in DB or not, and more, this tutorial don't work... can anyone please point me the way to a good solution? Ideias?! :D

Ty!