Comments by lodlaiden (Top 1 by date)

Your listening to the "TextChanged" event, which is a frequent event.
You may want to have your code firing on a LostFocus or Leave event.

Web code, by the nature of the platform, is less tightly bound to the user.

I'm working through the same issue with the custom validator posting to the server even though the javascript function is failing validation.
If you found an answer, I'd like to see it.

Lodlaiden