
Developing Web Applications • Chapter 10 489
Each of these controls can be attached to ASP.NET server controls (input
controls).You can also attach multiple validation controls to an input control.
Once these controls are attached to the input control, .NET Framework validates
the user inputs and, if there is an error, displays the error message on the page.
Furthermore, it sets the IsValid property of the Page object, which can be used to
check the page’s validity.
Among these validation controls, the RegularExpressionValidator control is
used to validate the user inputs with a predefined regular expression pattern.
Regular expressions are a powerful ...