Simple Validation approach in ASP.NETJun 02, 2015
An important aspect of creating ASP.NET Web pages for user input is to be able to check that the information entered by users is valid or not. ASP.NET provides a set of validation controls that provide an easy-to-use but powerful way to check for errors and, if necessary, display messages to the user.
You can add input validation to ASP.NET Web pages using validation controls. Validation controls provide an easy-to-use mechanism for all common types of standard validation for example, testing for valid dates or values within a range—plus ways to provide custom-written validation. In addition, validation controls allow you to customize how error information is displayed to the user.Validation controls can be used with both HTML and Web server controls.
The very good advantage of validation in asp.net is the support for both client side and server side validations.