Why you MUST use client side validation

Client side validation is checking the values against the desired format before sending them to server side for further processing. Javascript is used for validations on browser. Lately, with the popularity of jQuery, a large number of validation plugins are available which make it even more easy to implement validations on forms.

A word of caution before beginning. Though client side validation is very useful and simple to implement, it should NEVER be thought of as a...