The board may hire a director when it so deems one necessary and when sufficient funds have been appropriated. The director shall serve at the board's will and pleasure. He shall be the chief administrative officer of the school and shall administer the school in accordance with policies established by the board. The director shall be responsible for such administrative duties and functions as the board shall so prescribe. The board shall be authorized, in its discretion, to delegate to the director such of its powers and duties as it deems appropriate.