phone validation

Hi, I have to validate a phone which is divide up into 3 textboxes. I have the custom validator build on the server side, how do I make one for the client side to validate the 3 fields? How to pass the parameters to javascript? Here is my server side validator.

args.IsValid = Regex.IsMatch(txtPhoneAreaCode.Text, @"^\d{3}$") && Regex.IsMatch(txtPhonePrefix.Text, @"^\d{3}$") && Regex.IsMatch(txtPhoneLast4.Text, @"^\d{4}$");

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