A person or member of a board or body charged with or having the control of a State office, division, department or institution or a member of a county or municipal governing body or a member of a board of education, commits a crime of the fourth degree if he purposely and knowingly:
a. Disburses, orders or votes for the disbursement of public moneys, in excess of the appropriation for that office, division, department, institution, board or body; or
b. Incurs obligations in excess of the appropriation and limit of expenditure provided by law for that office, division, department, institution, board or body.
Nothing contained in this section shall be construed to prevent a board of education from keeping open the public schools.