The Required Field Validator is actually very simple, and yet very useful.

You can use it to make sure that the user has entered something in a Text Box control.

The server side validation routine must be called from the control's Server Validate event handler. The basic syntax for the control is as given: The Validation Summary control does not perform any validation but shows a summary of all errors in the page.

The server side validation routine should be written in any . The summary displays the values of the Error Message property of all validation controls that failed validation.

The validation control classes are inherited from the Base Validator class hence they inherit its properties and methods.

Therefore, it would help to take a look at the properties and the methods of this base class, which are common for all the validation controls: The Regular Expression Validator allows validating the input text by matching against a pattern of a regular expression.

These pages will show how to process PHP forms with security in mind.

Proper validation of form data is important to protect your form from hackers and spammers!

I'm sure that all the attributes of the controls makes sense by now, so I won't go into details about them. You should see something like this: If your browser supports Java Script, which most modern browers do, then you will notice that the page is not being posted back to the server - the validation is performed clientside! To see how it feels, you can add enableclientscript="false" to the Required Field Validator and try again.

Shannon Horn is the co-founder and chief software architect of Web Geniuses Corporation ( Hence, many times validation was not performed in a uniform manner, complex validation was difficult to implement, and Web servers were vulnerable to validation scripts being modified by malicious users.

He is a Microsoft Certified Application Developer (MCAD), Microsoft Certified Solution Developer (MCSD) and a Microsoft Certified Trainer (MCT) who has been developing Microsoft Windows and Web-based solutions as well as training for over 12 years. Shannon lives in Glendale, AZ, and is married with two daughters and a son. Validating the information entered by users is an essential part of developing a professional Web-based user interface.

The following two mutually inclusive properties list out the error message: Complex pages have different groups of information provided in different panels.

In such situation, a need might arise for performing validation separately for separate group.