All warrants drawn upon the city treasury must be signed by the Mayor and countersigned by the City Clerk, stating the particular fund to which the warrant is chargeable, the person to whom payable, and for what particular object. No money shall be otherwise paid than upon warrants so drawn. Each warrant shall specify the amount included in the adopted budget statement for the fund upon which it is drawn and the amount already expended of such fund.
(Neb. RS 17-711) ('72 Code, § 1-812)