Introduction

Forms usually expect the user to behave in a certain way and to insert data as requested. This is where data validations come in. Server-side validation is always a must to do and form validation at the client side should be considered.

Validation makes the application user-friendly, saves time and bandwidth. Client-side and server-side validation complement each other and they should be used always. In this chapter, we are going to look at some new mechanisms provided mostly for client-side checks by HTML5 as well as how to tackle some common problems.