This appeal is from a decree dissolving a temporary injunction. The impropriety of this decree is the only error assigned. The bill was filed by the appellants, as residents and taxpayers,- against the appellees in their official capacity as county commissioners, to enjoin the allowance and payment of claims for extra work performed by the contractor in the construction of a county courthouse. The answer of the respondents denied fully and particularly every averment of the original and amended bills which could be said to give them equity or to authorize a temporary injunction. We fully agree with and concur in the opinion of the learned chancellor that the injunction should be dissolv-. ed.
The original bill was clearly without equity. The amended bill, while it may contain equity, was subject to demurrer; but the sustaining of the demurrer thereto is not assigned as error. The answer having explicitly and fully denied every possible equity of the bill, we think the chancellor properly dissolved the injunction, and, while the chancellor has a large discretion on such hearings, we are not prepared to say it would not have been revisable error to retain this injunction on the show*598ing which appears from.this record. Equity will often interpose, in behalf of taxpayers, to restrain illegal acts of public officers under color and claim of official authority, when such acts tend to impair public rights and those of the taxpayers, or will result in irreparable injury to private citizens. But mere negligence of official routine, not gross or wanton, mere error of judgment, or lack of experience, etc., in the absence of fraud, will not authorize courts of equity to enjoin public officers from doing acts authorized by law, whatever may be the opinion of the court or of the public as to the wisdom of such acts or the mode of doing them. The act sought to be enjoined must be unlawful, or the mode, manner, or extent of its execution must be fraudulent in fact or in law. — 1 Spelling Extraord. Relief, 483-508.
The county commissioners have the undoubted fight and power to build county courthouses, and to make contracts therefor, and to pass and allow valid claims of the contractor on such account. This is not only their right, but is their duty, which they can be forced to perform, or for a failure, so to do they can be made liable. The fact that they make a contract for buildings, such as courts may think inexpedient or improper, or not as good as they or other persons could make, is no ground to enjoin them from so contracting, or from carrying out the contract which they have made, within the line and scope of their powers and duties. — Matkin v. Marengo Co., 137 Ala. 155, 34 South. 171; Hays v. Ahldrich, 115 Ala. 239, 22 South. 465. Of course, if they make an official contract for the purpose of defrauding the public and for their individual benefit, under color of official right and as a cloak to hide fraud, and by virtue of such official contract or act attempt to have public funds applied, not for the use and benefit of the public but foe *599their own personal benefit, or for that of a third party with whom they contract, then a court of equity would enjoin the execution of such a contract, though it was ostensibly for the public good and within the line of their powers and duties. If there can be said to be any such averments in this bill, they are vague and uncertain,' and rest largely upon inference; and they were, so far as it ivas necessary so to do, fully denied by the answer, and there was certainly not sufficient proof otherwise to justify the injunction. — Harrison v. Yerby, 87 Ala. 185, 6 South. 3.
There was certainly nothing in the contention of the original bill that the contract for the building was in writing and provided that there should be no change or alternation in the plans and specifications or contract except upon the written order of the commissioner’s court, and that the contractor had filed a claim with the commissioner’s court for a large sum which was claimed for extra work, not provided for in the contract, and for which there had been no written contract, and that such extra work was, therefore, illegal and in violation of the written contract. This provision was for the benefit of the parties thereto, and not for that of strangers. If both parties agree thereto, they may subsequently amend the whole contract, or any particular part, or make a new one in substitution therefor. Such new contract may be oral, as well as in writing. If the parties to a contract change it and substitute a new one, a third party or court cannot hold them to the first, though it be in writing and provide that its terms shall not be changed or varied except in writing, and the subsequent contract rest wholly in parol. If this were not true, ¿nd the commissioners’ court should malee a bad contract or the architect make a mistake in the specifications, the contract being in writing and providing that neither *600it nor tbe specifications should be changed, by writing or otherwise, then there would be no relief from the error, though both the commissioners and contractor be willing and desirous to make correction of the error.
The decree of the chancellor must be affirmed.
Affirmed.
Dowdell., C. J., and Anderson and McClellan, JJ., concur.