Chapter 3. Performing Form Validation with Validation Controls

IN THIS CHAPTER

• Using Client-side Validation

• Requiring Fields: The RequiredFieldValidator Control

• Validating Expressions: The RegularExpressionValidator Control

• Comparing Values: The CompareValidator Control

• Checking for a Range of Values: The RangeValidator Control

• Performing Custom Validation: The CustomValidator Control

• Disabling Validation

In this chapter, you learn how to use the Validation Web controls to validate the information that a user enters into an HTML form.

You can use the Validation controls to perform very different types of form validation tasks . For example, you can use the Validation controls to check whether a form field has a value, check whether the data in a form field falls in a certain range, or check whether a form field contains a valid e-mail address or phone number.

NOTE

You can view "live" versions of many of the code samples in this chapter by visiting the Superexpert Web site at:

http://www.Superexpert.com/AspNetUnleashed/

At the end of this chapter, you also learn how to create custom validation functions by using the CustomValidator control. Even if you need to perform a very specialized form validation task, you can do so by using this control.