In February 2000, CNS International Ministries, Inc., signed a contract with Eiman Brothers Roofing Systems. Under the contract, Eiman would provide CNS with a clay tile roof for one of its properties. On the basis of the size of the roof provided in CNS's plans, the total amount of the contract was $52,731. In May 2000, Eiman realized that the plan provided by CNS underestimated the roof 's actual size, which required an additional 20 to 25 squares. Eiman, demanding a second contract, recalculated and rebid the project. In May 2000, CNS signed a contract modification proposal sent by Eiman, adding $23,000 in costs. With the work substantially complete, CNS noted problems in Eiman's performance and its alleged failure to deliver on assurances to correct those problems. Con- sequently, CNS ordered Eiman to stop working on the roof. Eiman then brought a breach-of-contract action. At the time of the alleged breach, CNS had paid a total of $29,000 on the contract. CNS claimed that the contract was unenforceable for lack of consideration, in that Eiman had a preexisting duty to CNS. Specifically, CNS argues that the May 2000 proposal called for Eiman to perform in exactly the same manner as that specified in the original contract. Did Eiman have a preexisting duty to CNS? Why or why not?