Abstract: A method and apparatus for preventing a person from leaving an enclosed space having a door while leaving an article behind, such as preventing a driver from leaving an automobile while leaving the ignition keys within the automobile. Sensing elements are mounted on opposite sides of the door and a sensing device is located with the person. A shield which is adapted to cover the sensed element is attached to the ignition key. When the driver leaves the car without the ignition key, and without the shield covering the sensed element, the sensing device sounds an audible or visual alarm.