Jerome Jones, superintendent of the St. Louis Public Schools, suspended Edgar Toole, Jr., from his tenured teaching position as an Assistant Naval Science Instructor. Thereafter, on Jones’ recommendation and following a hearing, the Board of Education terminated Toole’s employment. Toole’s termination was affirmed by the Circuit Court.
Toole’s brief on appeal contains two points relied on. First, there was no competent and substantial evidence that either Toole’s school principal or Naval Science Instructor had authority to order him to go on extended field trips; because the order (1) is not supported by CNETINST 1533.9F, (2) is in conflict with the Superintendent’s Statement of Personnel Practices, and (3) is not authorized under Toole’s Permanent Teacher Contract. Second, Toole was discriminated against in violation of the Fourteenth Amendment to the Constitution; because the procedure for terminating a teacher in a metropolitan district is differ*378ent than the procedure in all other districts. Finding no error, we affirm.
Our review of the Board’s action is limited:
‘The reviewing court may only determine whether the board could reasonably have made its findings and reached its result or whether the decision was clearly contrary to the overwhelming weight of the evidence, [citation omitted]. The court may not substitute its judgment on the evidence and may not set aside the board’s decision unless it is not supported by competent and substantial evidence on the whole record. In addition, the evidence must be considered in a light most favorable to the board’s decision, together with all reasonable inferences which support it. [citation omitted]. If evidence before an administrative body would warrant either of two opposed findings, the reviewing court is bound by the administrative determination, and it is irrelevant that there is supportive evidence for the contrary finding, [citation omitted]. Also the determination of the credibility of the witnesses is a function of the administrative tribunal.’
Board of Educ., Mt. Vernon Schools v. Shank, 542 S.W.2d 779, 781-82 (Mo.banc 1976) (quoting Merideth v. Board of Educ. of Rockwood R-6 School Dist., 513 S.W.2d 740, 745 (Mo.App.E.D.1974)). Viewing the record in light of these principles, there is competent and substantial evidence to support the conclusion that there was authority to order Toole to go on extended field trips, and that Toole refused to go.
As required by Shank, we must consider the evidence “in a light most favorable to the board’s decision.” The evidence discloses that in 1980, the Board contracted with the Department of the Navy to establish a unit of the Naval Junior Reserve Officers’ Training Corps. Although the NJROTC program is under the direct control of the Board, it is subject to Navy rules and regulations.
The contract requires the program be directed by a Naval Science Instructor (NSI). One or more Assistant Naval Science Instructors (ANSI) must also be employed by the Board. The NSI and ANSIs must be retired officers or enlisted personnel from the Navy, Marine Corps, or Coast Guard, approved and certified by the Chief of Naval Education and Training (CNET).
The principal at the school where the program began was John Close, Clinton Land was the NSI. Apparently there were three ANSIs, including Toole.
Under Land’s leadership, he and the ANSIs would meet each August and plan field trips for the year. After the locations of the trips were determined, Toole said Land would ask “who wants to go on what field trips, and each one of [the ANSIs] stated [a] preference.” According to Toole, “if there was a question about who was going on what field trip, we might flip a coin or I might say, well, I really don’t want to go on that one, you go, John, but we agreed among ourselves who was going on what field trip.”
In 1985, Ivory Lofton replaced Close as principal. Thereafter, Betty Gabryshak replaced Land as NSI. She had previously been an ANSI for four years with Toole.
Gabryshak scheduled field trips for the 1986-87 school year. Unlike the previous NSI, she did not hold a meeting to determine the ANSIs’ preferences. Rather, she circulated a memorandum to the ANSIs, indicating that two persons were needed for each trip and they should sign up for those trips in which they were interested. The memorandum also said, “if you do not sign up, you will be assigned.”
The sign-up memorandum was routed to the ANSIs on the basis of prior military rank. Toole thought this was unfair, since all were now civilians and not military personnel. As a result of this routing method, Toole said he “must have been the next-to-the-last person to get [the memorandum].”
According to Toole, there were six trips on the list. When he received the list, two people had already signed up for each trip. Toole said he “didn’t want to go on any of the trips and [Gabryshak] had ample volunteers, so I did not volunteer for any field trips, period.”
*379With the exception of Toole, all the ANSIs signed up. Since Toole did not, Ga-bryshak assigned him to field trips to Pensacola, Florida, and Norfolk, Virginia.
The Pensacola trip was scheduled for December 15 through 18, 1986. The necessary form for Toole to sign to go on the trip was prepared, but Toole did not sign it. Gabryshak then met with Toole and discussed CNETINST 1533.9 with him.
CNETINST 1533.9 is the basic Navy regulation for the operation of NJROTCs. It sets forth guidelines for specific duties and responsibilities of the NSI and ANSI. Ga-bryshak discussed § 406b(7) with Toole. This section provides that an ANSI’s duties include “[p]lanning and conducting extracurricular activities for NJROTC unit (including ... field trips, mini-boot camps, ship cruises, etc.).” Toole told her that he was not going on the field trip.
Gabryshak reported Toole’s refusal to Principal Lofton. On approximately November 12, Lofton met with Toole. Lofton ordered Toole to go on the trip. According to Lofton, Toole said that he was not going and offered no reason for his refusal.1 In a letter to Lofton concerning that meeting, Toole stated he “had no intentions of taking any extended out of town field trip with cadets in attendance unless adequate compensation was considered. [NSI] Gabrys-hak had been previously so informed.”
On November 13, Lofton sent Toole a form to sign for the field trip. The form is titled “Request for Leave of Absence.” Lofton testified that this form is used to account for teachers when they are away from their assigned school building. According to Gabryshak, it is the standard application form used by ANSIs “on these field trips.” Although the form’s title and wording could cause confusion, there is no evidence that its format was previously questioned.
The form for the Pensacola trip shows that the purpose for the absence was “Navy orientation visit.” It also shows that the absence was to be with salary. Toole would not have been charged with any time off by signing this form and taking the field trip.
On November 14, Lofton sent Toole another memorandum. In that memorandum, Lofton quoted paragraph 7 of CNETINST 1533.9F concerning an ANSI’s duty and responsibility to plan and conduct field trips. He also pointed out that ANSIs are to follow orders, and he concurred with the NSI in assigning this trip to him. The memorandum concluded: “If you, at the time of this field trip, follow your current posture and refuse to go, you will be considered insubordinate and the appropriate disciplinary action will be instituted.”
On December 15, the day the cadets left on the Pensacola trip, Toole reported to work, but did hot go on the trip. Gabrys-hak went in his place.
That same day, Gabryshak filed a special evaluation of Toole with the CNET. She *380advised the CNET of Toole’s actions, and requested that the CNET decertify Toole.
By letter dated February 17, 1987, the CNET advised Toole that the special evaluation, as well as evidence Toole submitted, had been reviewed. The letter continued:
Your NSI has responsibility to assign you duties within the guidelines of this instruction. “Planning and conducting extracurricular activities for [the] NJROTC unit (including ... field trips ...)” is a specific duty expected of all ANSI’s in the NJROTC program. You cannot be an exception. Accordingly, you are advised that further refusal on your part to fulfill any duty properly assigned by your NSI will result in action to terminate your certification.
Toole continued as an ANSI, and was still scheduled to take the Norfolk trip on April 27. On March 23, Gabryshak called Toole to have him sign the necessary form. Toole told her that (1) he was not going, (2) he did not like the selection process, and (3) he did not like the idea of two ANSIs going. According to Gabryshak, Toole also said that he would say “he’s not going because they’re not paying him”2 and that “he’ll see us in court.” Lofton also spoke with Toole and Toole refused to go; Lofton told Toole he would forward Toole’s refusal to Lofton’s superior.
On April 3,1987, the Superintendent suspended Toole without pay. Two charges were set forth in the Statement of Charges which accompanied the suspension notice. The charges alleged violations of Board regulations 5210 and 5346. Regulation 5210 requires employees to “obey all lawful orders and directives issued by their superiors .... Failure to so act shall constitute insubordination in the line of duty.” Regulation 5346 provides that such failure to obey “shall be grounds for disciplinary action against an employee, including dismissal.”
The first charge specified failure “to obey a lawful order and directive issued by a superior, Ivory Lofton, ... that you accompany thirty-seven Cadets on an educational field trip to Pensacola, Florida, on December 15, 1986.” In support of this allegation, the charge noted that Lofton directed Toole to sign the appropriate form, but that the form was returned unsigned.
The second charge specified failure “to obey a lawful order and directive issued by a superior ... Gabryshak, that you complete and execute appropriate forms to accompany Cadets on an educational field trip to Norfolk, Virginia, on April 27, 1987.” The charge noted that Gabryshak contacted Toole about the forms, and that Toole told Gabryshak that he was not going on the trip because he was not getting paid.
Toole’s first point on appeal is that the “Superintendent failed to show by competent and substantial evidence that Principal Lofton or N.S.I. Gabryshak had authority to order [Toole] to volunteer3 for an extended field trip.” Toole alleges that the order (1) is not supported by CNETINST 1533.9F, (2) is in conflict with the Superintendent’s Statement of Personnel Practices, and (3) is not authorized under Toole’s Permanent Teacher Contract.
*381Toole does not argue that the school principal and the NSI were not in supervisory positions over him. Rather, his first allegation is that the order is not supported by CNETINST 1533.9F. As noted earlier, section 406b(7) of CNETINST 1533.9F establishes guidelines for “specific duties and responsibilities of the ANSI.” That section provides that an ANSI’s duties include planning and “conducting” field trips. Section 406 also provides that ANSIs “shall perform such duties as may be assigned them by the NSI.” Contrary to Toole’s allegation, CNETINST 1533.9F supports the order.
Toole further argues that CNETINST 1533.9F is applicable only to those situations where there is a single unit of NJROTC in a school. He contends that it does not apply when, as here, an entire school is devoted to NJROTC.
Congress established minimum requirements for schools to qualify for a NJROTC program. It did not, however, establish a maximum number of students allowed in a unit. 10 U.S.C. § 2031 (1989). Toole does not refer us to any statute, regulation, or decision placing such a limitation on the applicability of CNETINST 1533.9F.
Further, in an August 27, 1986 letter to the Superintendent, Toole stated that from the time the program commenced in 1981, “insofar as possible, we began in compliance with CNET INSTRUCTION 1533.” Finally, the CNET’s February 17, 1987 letter to Toole specifically directed him to comply with CNETINST 1533.9F, thus indicating that the CNET also applied that regulation to the activities at the school.
Toole next alleges that the order conflicts with the Superintendent’s Statement of Personnel Practices of July 9, 1986. He points to a provision in that document that the ANSIs’ work day schedule shall be the same as for all other regular classroom teachers. Further, the document provides that working conditions approved for regular teachers are applicable to ANSIs. Toole argues that ordering an ANSI to go on an extended field trip violates that policy.
Requiring an ANSI to go on extended overnight field trips does not violate that policy. The Associate Superintendent for Personnel testified that some of the district’s classroom teachers are required to go on extended overnight field trips.
We also note that the meeting which preceded the July 9 memorandum was called to discuss the ANSIs’ personnel concerns. Before that meeting, at the request of the Associate Superintendent for Personnel, Toole set forth specific concerns and those concerns were discussed. Nothing in the record indicates that a concern was raised as to whether ANSIs were required to go on field trips.
It is understandable that no such concern was raised. Toole testified that, from the very beginning of his employment, field trips were a part of the program. He said he did not know how many field trips he had taken, whether it “was ten, fifteen, twenty, I really don’t know, but we went on x-number of field trips each year depending on what we thought was sufficient to keep the kids interested in the program.” Further, Toole said that he “agreed to go on field trips at no cost to the Navy, because we had to do this in order to keep the job.” Thus, the Board could have reasonably believed that Toole knew that extended field trips were a requirement of the position. The July 9 memorandum is not in conflict with this long standing requirement.
Finally, under this point, Toole alleges that the order was not authorized under his Permanent Teacher Contract. This point was not developed in the argument section of the brief. Thus, it is deemed abandoned, and is denied. Pate v. St. Louis Indep. Packing Co., 428 S.W.2d 744, 751 (Mo.App.E.D.1968); LoPiccolo v. LoPiccolo, 547 S.W.2d 501, 506 (Mo.App., E.D.1977); see Bopp v. Spainhower, 519 S.W.2d 281, 286 (Mo.banc 1975).
Moreover, the record does not support Toole’s allegation. As previously indicated, the Associate Superintendent of Personnel testified that as part of their performance requirement, some of the district’s teachers are required to go on extended overnight *382field trips. For cases discussing assignment of teachers to supervise trips, see, e.g., Parrish v. Moss, 106 N.Y.S.2d 577, 200 Misc. 875 (N.Y.Sup.Ct.1951), aff'd 279 A.D. 608, 107 N.Y.S.2d 580 (N.Y.App.Div. 1951); District 300 Educ. Ass’n. v. Board of Educ. of Dundee Community Unit School Dist. No. 300, 31 Ill.App.3d 550, 334 N.E.2d 165 (1975); McGrath v. Burkhard, 131 Cal.App.2d 367, 280 P.2d 864 (1955). Point denied.
Toole’s second point relied on alleges that he was denied procedural and substantive due process rights, as well as equal protection rights, because he was employed in a metropolitan school district. These denials, he alleges, result from the “radically different” procedures for terminating teachers in a metropolitan district compared to those used in all other school districts.
We first observe that suspension and termination of teachers in a metropolitan school district4 is regulated by § 168.221, RSMo 1986. This regulation was recognized in Toole’s Permanent Teacher Contract. The Board and Toole specifically agreed that Toole would be “subject to removal only as provided in Section 168.221 R.S.Mo.”
The pertinent portions of § 168.221 have been in existence since at least 1963. The probationary period for teachers and principals is three years. § 168.221.1. Permanent teachers and principals may be removed only for a cause delineated in § 168.221.3. The Board has the authority to fire a teacher “for a one time violation of Board regulations, even in the absence of a showing that the violation was willful.” Westbrook v. Board of Educ., 724 S.W.2d 698, 701 (Mo.App.E.D.1987).
Suspension and termination of non-metropolitan school district teachers is regulated by § 168.114, RSMo 1986. The probationary period for these teachers is five years. § 168.104(5), RSMo 1986. A permanent teacher may be terminated only for a cause described in § 168.114. If the cause is “incompetency, inefficiency, or insubordination in line of duty,” a 30 day advance warning is required. § 168.116.2, RSMo 1986.
Preliminarily, Toole argues that the circuit court erred in holding that § 168.221 is controlling. The court did not err. See Westbrook, supra, at 701.
Toole further states that teachers in non-metropolitan school districts are afforded “greater procedural protection” than teachers in metropolitan school districts. This, he argues, violates the equal protection clause.
To establish such a violation, Toole must prove “that there is no rational connection” between the General Assembly’s classification of school districts and its objectives. Harrah Indep. School Dist. v. Martin, 440 U.S. 194, 198, 99 S.Ct. 1062, 1064, 59 L.Ed.2d 248, 254 (1979). Toole presented no evidence that the General Assembly’s classification is irrational. His point is denied.
The judgment of the trial court is affirmed.
GARY M. GAERTNER, J., concurs. KAROHL, J., dissents in separate opinion.. In the spring of 1986, the ANSIs met with the Associate Superintendent for Personnel and discussed working conditions. There is no indication that any question was raised at that meeting as to whether ANSIs were required to go on field trips. On July 9, the Associate Superintendent responded in writing to the questions discussed at the meeting.
On August 27, Toole wrote the Superintendent, raising seven questions, including "Are ANSIs required to go on extended field trips? If so, what are the circumstances?” His letter then continues:
The above questions are not specifically addressed in CNET INSTRUCTION 1533. In a NJROTC "UNIT”; there will not normally be a "seniority” problem among the military staff; there will not normally exist “resentment" and "envy” between the military and civilian staff; there will not normally be "conflict” between the ANSI and the NSI; ... there will not normally exist any reason for "comparing” salary; and there will not normally exist any reason to “question” field trips between or among ANSIs and the NSI.
His letter then mentions that the original three ANSIs receive only $1000 per year over the minimum salary, while newer ANSIs receive $2000. He requested a raise to $2500 per year over the minimum.
On September 22, a response was sent to Toole. It said that his first six questions were answered in the July 9 letter. As to his question about field trips, he was told to "discuss this matter with your immediate supervisor. It is this Office’s belief that field trips are a performance requirement.” His request for a raise was denied.
. As with the Pensacola trip, the form provided that Toole was to receive his salary while on this trip.
. The record is replete with references to the word "volunteer.” It is clear, however, that the word was not used in its ordinary sense. Rather, it was used in the sense of expressing a preference for assignment to particular field trips.
Toole’s testimony supports this interpretation. Under the first NSI, the NSI and ANSIs met, and according to Toole, "agreed among ourselves who was going on what field trip.” Toole said the NSI "asked who wants to go on what field trips, and each one of us stated our preference." (Emphasis added). Later, Toole was asked; “Did you volunteer for some of these [earlier] field trips?” Toole responded, "I volunteered for every one that I went on.” (Emphasis added).
This interpretation is also supported by Ga-bryshak’s testimony concerning her procedure. She said, "we need two persons per trip and [ANSIs] please sign up for those that you are interested in, because quite frankly some people are not interested in going to see aviation, or submarines or whatever, and when this happens, I also say that if you do not sign up, you will be assigned.” One would not be subject to assignment if the trips were purely voluntary.
. “Every city in this state, not within a county, ... constitutes a single metropolitan school district, and is a body corporate.” § 162.571, RSMo 1986.