MaskedEditValidator, part of the AjaxControlToolkit is a custom validator which attaches to the MaskedEdit extender and its associated TextBox and verifies that the input text matches the pattern specified in the MaskedEdit extender
MaskedEditValidator, part of the AjaxControlToolkit is a custom validator which attaches to the MaskedEdit extender and its associated TextBox and verifies that the input text matches the pattern specified in the MaskedEdit extender.
Taken from the MaskedEdit page on the AjaxControlToolkit sample site here.