Run custom Javascript whenever a client-side ASP.NET validator is triggered?

Question

Is there a way to run some custom Javascript whenever a client-side ASP.NET validator (RequiredFieldValidator, RangeValidator, etc) is triggered?

Basically, I have a complicated layout that requires I run a custom script whenever a DOM element is shown or hidden. I'm looking for a way to automatically run this script when a validator is displayed. (I'm using validators with Display="dynamic")

Answer 1

See this comment for how I managed to extend the ASP.Net client side validation. Others have managed to extend it using server side techniques.