Is JavaScript validation bad?

Question

It has been long time since we have been validating our forms using JavaScript. I am sure this must be the case with most other developers.

Question:

What if the

Answer 1

What if the user (or probably a bad guy) disables javascript?

As said before: Simply do not rely on the client. Never do so. Check everything on the server again.

Should we ever use it now?

Yes - so the user immediately sees what's wrong. Otherwise he had to post back the data first which may take a while. By the way you reduce traffic to your server.

It's simply more inuitive.

//EDIT: BTW: The ASP.NET ValidationRules contain both client-side and server validation as far as I know.