The validator controls that ship with ASP.NET only have the ability to validate a single form field. While they save time and simplify development, they aren't practical for the common task of validating groups of fields like CheckBoxLists, RadioButtonLists, several checkboxes, credit card information (name on card, card number, card type, and expiration), etc. ASP.NET Group Validator includes design-time support for Visual Studio.NET and ASP.NET Matrix. It includes complete documentation and a sample form to get you started.