form registration popup with hints

Do You know any good plugins which are suposed to display hints popups each time user c开发者_如何学Changes form field. For example when user enters password field there should appear popup with information that password should have at least 8 characters. That just an example. Thanks for help.

The jQuery Validation plugin is the de facto standard these days.

...but if you're using ASP.NET, you already get input validation for next-to-free:

• Elegant way to combine ASP.NET validation with JQuery
• jQuery Validation plugin in ASP.NET Web Forms

Take a look at http://docs.jquery.com/Plugins/validation