Where do the ASP.NET validation controls validate data, on the Client or on the Web Server?-tech17032012

ASP.NET validation controls validate data first on the client and then on the web server. If a client disables javascript on the browser then, client side validations are bypassed and validations are performed on the web server. Client-side validation is provided by a JScript library named WebUIValidation.js, which is downloaded separately to the client. Validation controls also automatically provide server-side validation. Server-side validation is always performed, whether or not client-side validation has occurred. This double-checking ensures that custom validations are performed correctly and that client-side validation has not been circumvented.