Surely these articles will help you. It should put you in the right
direction if your looking to extend validator controls.
"Tomk" <tomk20hotmail.com> wrote in message
news:%23VpotOs2DHA.2208TK2MSFTNGP12.phx.gbl...an> I would like to have a RegularExpressionValidator that would also requirereturns> entry. So I opened Reflector and looked at the RegularExpressionValidator
> control and found the EvaluateIsValid function. In this function ittest> a true if the ControlToValidate is empty. OK so my thought was to extend
> this control, add a 'Required' property and override the EvaluateIsValid
> function. Then return false if the 'Required' property is set and the
> ControlToValidate is empty. This all seem to work just fine and on my> program it seemed to work. However in real practice I found that if the
> ControlToValidate was empty the form was still submitted. So is seems I
> have to dig into the JScript generated by the control. Am I going in the
> right direction? What do I override to change the JScript?