Implement validation using ajax along with php

Question

I am building a website using php+mysql. I have a registration page and its already implemented in php. Now i would like to make the page more dynamic and interactive using ajax.That is i would like to have a feature in which when user moves to next tab it should display message in previous field saying right/wrong depending on user entered data. Can anyone let me know is it possible to add this feature to already php page or should i start from scratch. Please let me know if any good sources for learning ajax

Answer 1

See this: http://www.w3schools.com/Ajax/Default.Asp to learn about Ajax, or you could jump directly to Ajax on Wikipedia. A very important thing is to remember that even if you validate the fields using Ajax, you should always verify and sanitize the input on the server when the form is processed, because web requests can be easily faked.