MSDN Article - Developing a Validator Control. There are also alternatives to ASP.NET's built in validation controls that function the same but work in other browsers - DOM-Compliant Validator Controls (also available on Glavs Homepage at ASPAlliance.com) The site seems to have a CSS bug that makes it display incorrectly in Firefox/Mozilla. There is a feedback form for contacting the WebMaster (fix is to remove the
height: 33px; line in the
div.abstract class in the stylesheet
The validation controls in the next version of ASP.NET should work in browsers other than IE.