The officers of the corporation shall consist of a chairman, a vice-chairman, a secretary, a treasurer and such other officers as the board of directors shall deem necessary to accomplish the purposes for which the corporation was organized. The chairman and the vice-chairman of the corporation shall be elected by the board of directors from its membership, but neither the secretary, the treasurer nor any of the other officers of the corporation need be a member of the board of directors. The offices of secretary and treasurer may, but need not be, held by the same person. The chairman and the vice-chairman of the corporation shall be elected by the board of directors for a term of one year, and the secretary, the treasurer and the other officers of the corporation shall be elected by the board of directors for such terms as it deems advisable. The board of directors shall have also the authority to employ all personnel as it deems necessary and to fix the terms and conditions of their employment. The duties of the chairman, vice-chairman, secretary and treasurer shall be such as are customarily performed by such officers and as may be prescribed by the board of directors. The duties of any other officers of the corporation shall be such as are from time to time prescribed by the board.