Loren Vranich, a doctor practicing under the corporate name Family Health Care, P. C., entered into a written employment contract to hire Dennis Winkel. The contract provided for an annual salary, insurance benefits, and other employment benefits. Another doctor, Dr. Quan, also practiced with Dr. Vranich. About 9 months later, when Dr. Quan left the practice, Vranich and Winkel entered into an oral modification of their written contract whereby Winkel was to receive a higher salary and a profit sharing bonus. During the next year, Winkel received the increased salary. However, a disagreement arose, and Winkel sued to recover the profit sharing bonus. Under Montana law, a written contract can be altered only in writing or by an executed oral agreement. Dr. Vranich argued that the contract could not be enforced because it was not in writing. Does Winkel receive the profit sharing bonus? Is it ethical of Dr. Vranich to raise the defense that the contract is not in writing? Winkel v. Family Health Care, P. C., 668 P. 2d 208, 1983 Mont. Lexis 785 (Supreme Court of Montana)