Section 38. A grand or trial juror may be permitted by the court to be available for juror service or continued juror service upon telephone notice. A juror who agrees to be available on telephone notice shall provide to the court a telephone number and a named individual by which he may be notified with certainty during court hours to begin or resume his juror service not more than one hour after such notice has been given. Such juror shall conduct his affairs during court hours so that he shall insure his compliance with the conditions of telephone notice.