Client Side Validation(Java Script)

[Garandi Garandi]

I am trying to do client side validation.
Q1: This is signature of validateRequired(form) which is inside javascript tag.
How to access different fields from "form" in order to validate them?

Q2: I have to do some server side custom validation too.
Where to put my validation .class files in order for validation to find them?
Thank you in advance
Garandi