Ketchup is flexible and extendible form validation plugin that allows you to easily control its appearance and functionality. Powered by jQuery, you can extend it to add more validation rules that fit your needs. If you don’t prefer the default styling you can easily change it as well to match your theme.
The main strength of this plugin over other validation plugin is the way code has been organized. It is divided into three files: core , messages and validation that enables developers to easily extend any part of the script. The look and feel can easily be modified by changing the CSS file.
Developed by Sebastian Senf; Ketchup jQuery Plugin is available for download under MIT and GPL licenses. You can find further information, demo & download on Ketchup jQuery Plugin Website.