Return true if valid phone number

gistfile1.txt

    function isValidUSPhoneNum(number) {
        var USPhoneNumRegex = /^(?:\([2-9]{3}\)(?:[\s]*|[-])|[2-9]{3}(?:[\s]*|[-]))[0-9]{3}(?:[\s]*|[-])[0-9]{4}$/;

        // booleanize
        return !!number.match(USPhoneNumRegex);
    }