My strategy for elevator saga http://play.elevatorsaga.com/

Elevator saga

// The only small improvement from challange #3 was 
// manipulating the elevator light

{
    init: function(elevators, floors) {
        elevators.forEach(function(elevator){
            elevator.on("floor_button_pressed", function(floorNum) {
                elevator.goToFloor(floorNum);
            });

            floors.forEach(function(floor) {
                floor.on("up_button_pressed", function() {
                    elevator.goToFloor(floor.floorNum());
                    elevator.goingUpIndicator(true);
                    elevator.goingDownIndicator(true);
                });
                floor.on("down_button_pressed", function() {
                    elevator.goToFloor(floor.floorNum());
                });

            }); 
        });
    },
    update: function(dt, elevators, floors) {
        // We normally don't need to do anything here
    }
}