Before any minor may be employed or continue to be employed in connection with any gainful occupation, the employer shall require proof of the age of the minor employee or prospective employee by requiring the minor to provide the employer with a copy of the minor's birth certificate, passport, driver's license or state issued identification. If the evidence is not available, the parents or guardian shall appear with the minor before the judge or other officer of the juvenile court of the county in which the minor resides and shall make an oath as to the age of the minor.