Sams Teach Yourself Visual Studio® .NET 2003 in 21 Days

Using Validation Controls

Visual Studio .NET comes with built-in validation controls for use in ASPX pages. When you validate a control, you're checking whether a control has data in it and conforms to a specific pattern, (such as an email address), or you're checking the range of data that has been entered.

In ASP, you either had to process the validation on the server and send the page back to the browser if data wasn't correctly entered, or you had to write complex JavaScript to check the validity of control data. ASP.NET has five built-in validation controls in the Toolbox that you can simply drag to a form and associate with a control. Table 5.2 lists the validation controls and gives a description of how you can use each one.

Table 5.2. ...