Tom Mollerus' Weblog

I've just come back from an CommonSpot Advanced Developer's Training class, where some people expressed the thought that server-side validation wasn't required as long as you have sufficient client-side validation through JavaScript. Then this morning I read Mark Kruger's excellent (if rather unfortunate) example of why you should always implement server-side data validation in your applications. Always remember that users, whether friendly or malicious, can submit anything they please via form submissions, URL query strings, or even cookies.