Ever needed to ensure that a user typed an email address into a text box? Or wanted to make sure that a user typed numbers only into a phone number field? Validation involves checking that the data your application’s users have entered obeys a number of predefined rules. To help developers with the most common data validation tasks, ASP.NET provides a set of validation controls that ease the problems that troubled web developers in the past. This chapter will show you how to use them.
More specifically, in this chapter you will:
Learn the difference between client-side and server-side data validation.
Use the .NET validation controls to restrict the data your visitors can submit.
Create validation groups ...