はてなブックマーク

This jQuery plugin makes simple clientside form validation easy, whilst still offering plenty of customization options. It makes a good choice if you’re building something new from scratch, but also when you’re trying to integrate something into an existing application with lots of existing markup. The plugin comes bundled with a useful set of validation methods, including URL and email validation

link Validate forms like you've never validated before! "But doesn't jQuery make it easy to write your own validation plugin?" Sure, but there are still a lot of subtleties to take care of: You need a standard library of validation methods (such as emails, URLs, credit card numbers). You need to place error messages in the DOM and show and hide them when appropriate. You want to react to more than