See Demo Here: http://brentonstrine.github.io/instantiate/

#A Powerful yet Light-weight Validation Plugin

Instantiate is a powerful yet lightweight jQuery plugin that instantly validates user input as they type. Most validators wait until after users have already sumitted the form before they find out if they've made mistaakes, and in the worst cases, the error messages are not linked to the individual inputs, but just dumped at the top.

Instantiate solves all these problems by just validating right away on a per-input basis.

##Types of validation

Instantiate offers a range of ways to validate. At it's most simple, use the HTML attribute required. It also allows more complex validation using regular expressions, predefined or developer-added Javascript functions, or backend scripts via AJAX.

##Demos!

For a demo and an explanation of the different types of validation, see the demo page.

I've also put together a demo registration page so you can see the instant validator in action in a context that feels more realistic. I think you'll agree that this plugin provides the best UI and UX around.