If a contract has been performed on one side so that all that remains is an obligation to pay and a right to receive money, can the parties by agreement effectively prevent the assignment of the claim? The Illinois Supreme Court had this question before it for consideration in the case of State Street Furniture Co. v. Armour & Co., where the plaintiff was the assignee of wages due to an employee of the defendant, the employee having agreed not to assign his wages without the written consent of his employer. The court decided that the restrictive agreement had no effect, and permitted the plaintiff to recover in spite of the fact that the plaintiff had been given notice of the restriction by the employer before the assignment took place.