Hi,

no client script required

You can create variable validation Regex and then attach it to the Variable

Validate U.S Phone Numbers using JavaScript Regular expression.

This will work for these phone number formats

E.g (308)-135-7895 or 308-135-7895 or 308135-7895 or 3081357895

^\(?(\d{3})\)?[- ]?(\d{3})[- ]?(\d{4})$

If my response helped please mark it correct and close the thread so that it benefits future readers.

Regards
Ankur