In Posey v. Medical Center-West, 257 Ga. 55 (354 SE2d 417) (1987) the Supreme Court of Georgia addressed the question of whether a general release given to one joint tortfeasor released all joint tortfeasors, and adopted the following rule: "A valid release of one tortfeasor from liability for a harm, given by the injured person, does not discharge others for the same harm, unless it is agreed that it will discharge them." Id. at 59. The court further explained that where a plaintiff releases one joint tortfeasor he need not release all other joint tortfeasors, if he has not yet received full satisfaction. Id. at 58.