Before entering upon his or her duties, each judge or clerk of election and each inspector shall sign an oath to be returned to the county clerk after the polls close. The oath need not be taken and signed before a person authorized to administer oaths. If the oath is printed in the sign-in register, the signing of the sign-in register shall be complete and sufficient compliance with the requirements of section 11-101.01. The form of the oath shall be as provided in such section.