For those of you who don’t know, those sweet validators we use in WebForms are not available in Windows Forms. Greg Duncan has a post today that shows how to use an ExtenderProvider to create a RegEx validator in the same vein as the web one. MVP Billy Hollis had a similar article in 2003, and shows how to create several validators. For the time-pinched, you can find a current version of the sample at http://dotnetmasters.com/samples.htm.