This agreement contains a restrictive covenant. Restrictions to prevent competition by a former employee are held valid when they are reasonable and necessary to protect the interests of the employer. For example, a provision in an employment contract which prohibited an employee for two years from calling on any customer of the employer called on by the employee during the last six months of employment would generally be valid. Courts will closely examine covenants not to compete signed by individuals in order to make sure that they are not unreasonable as to time or geographical area. For example, suppose a company only operated within a certain city, and the covenant not to compete provided that an employee of the company could not solicit business in the city or within 100 miles of the city if he ever left the employ of the company. Such an agreement would be unreasonable as to its geographical area. The company had no need to be protected regarding such a large geographical area.