Validating user input is a very common task that we perform during web page development, and in the ASP.NET world we have a handful amount of choices to perform validation. ASP.NET Validation Controls ASP.NET ships with a handful amount ASP.NET Validation controls such as RequiredFieldValidator, CompareValidator, RangeValidator, RegularExpressionValidator, CustomValidator and ValidationSummary. These controls are very easy to hook up with other ASP.NET controls, and if properly configured they check ......