elevatorsaga works until level 6

gistfile1.js

{
  go: function (elevator) {
    var self = this;
    elevator.on("idle", function() {
      self.queue.push(elevator);
    });

    elevator.on('floor_button_pressed', function (floor) {
      elevator.goToFloor(floor);
    });
  },
  callElevator: function (floorNum) {
    var self = this;
    var elevator = self.queue.shift();
    if (elevator) {
      elevator.goToFloor(floorNum);
    } else {
      setTimeout(function () {
        self.callElevator(floorNum);
      }, 0);
    }
  },
  up: function (floor) {
    var self = this;
    floor.on("up_button_pressed", function(event) {
      self.callElevator(floor.floorNum());
    });
    floor.on("down_button_pressed", function(event) {
      self.callElevator(floor.floorNum());
    });
  },
  queue: [],
  init: function(elevators, floors) {
    for(var i = 0; i < floors.length; i++) {
      this.up(floors[i])
    }

    for (var i = 0; i < elevators.length; i++) {
      this.go(elevators[i]);
    }
  },
  update: function(dt, elevators, floors) {
    // We normally don't need to do anything here
  }
}