GUMP::validate_phone_number PHP Method

    protected function validate_phone_number($field, $input, $param = null)
    {
        if (!isset($input[$field]) || empty($input[$field])) {
            return;
        }
        $regex = '/^(\\d[\\s-]?)?[\\(\\[\\s-]{0,2}?\\d{3}[\\)\\]\\s-]{0,2}?\\d{3}[\\s-]?\\d{4}$/i';
        if (!preg_match($regex, $input[$field])) {
            return array('field' => $field, 'value' => $input[$field], 'rule' => __FUNCTION__, 'param' => $param);
        }
    }