In Witty v. McNeal Agency, 239 Ga. App. 554, 557-559 (2) (a), (b) (521 SE2d 619) (1999), the Court upheld the validity of a notice provision in an employment contract that required the employee to serve written notice of his resignation two weeks prior to terminating his employment relationship. See id. The time limitation in the employment contract was intended to afford the employer sufficient time to contact its clients before the employee began to work and solicit clients on behalf of a competitor. Id. at 554, 558 (2) (a).