I’ve ported my YUI Unobtrusive Javascript Validation script to Prototype, since that’s what I’m using these days. It has exactly the same features as it’s YUI brother, but the script is much smaller and has been structured much better.

• Preview the Prototype based Validation script
• Download the Prototype based Validation script (v2.1, 2008-10-22)
• Find out how to use the Script