Okay, didn't read or look (currentFloor is already defined) and this won't work in this context.

Here is another approach that brought me through till challenge #7:

{
init: function(elevators, floors) // hook up events
{
// these are the global wish lists that idle elevators choose from (key are floor numbers, values are number of people):
var wishListUp = {}, wishListDown = {};

for (var i = 0, l = elevators.length; i < l; i++)
{
var elevator = elevators[i];
// API: goToFloor(n) [enqueues], stop() [clears queue], currentFloor(),
// goingUpIndicator([set]), goingDownIndicator([set]), loadFactor() [0..1],
// destinationQueue[], checkDestinationQueue() [after manual update]

elevator.on("idle", function() // elevator destination queue finished
{
processWishList();
});

elevator.on("floor_button_pressed", function(floorNum) // passenger indicates where to go
{
if (this.destinationQueue.filter(function (d) { return d == floorNum; }).length == 0) // if not already enqueued
this.goToFloor(floorNum); // enqueue
// note: passengers coming first need to be delivered first (or at least at all)
// however, the elevator will check by passing, whether one destination
// can be approached before the others since it comes on the way.
});

elevator.on("passing_floor", function(floorNum, direction/*"up"/"down"*/) // if not in destination queue
{
updateIndicators(this); // indicate next destination from here
// we stop here if the queue contains this destination,
// or if a passenger on the global wish list want to go in our direction.
// we can only hope that people check where the elevator is going.
if (this.destinationQueue.filter(function(d) { return d == floorNum; }).length > 0)
{
this.destinationQueue = this.destinationQueue.filter(function(d) { return d != floorNum; }); // remove from later
this.destinationQueue.unshift(floorNum); // add as immediate next destination
this.checkDestinationQueue(); // announce modification
}
else if (this.loadFactor() < 1.0) // if there is some space left
{
switch (getDirection(this))
{
case 1: // going up
if (wishListUp[floorNum]) // are people waiting to go up from here?
{
//if ((1.0 - this.loadFactor()) * 10.0 - wishListUp[floorNum] > 0) // assume capacity for 10 people with regular weight
// delete wishListUp[floorNum]; // mark as visited
this.destinationQueue.unshift(floorNum); // add as immediate next destination
this.checkDestinationQueue(); // announce modification
}
break;
case -1: // going down
if (wishListDown[floorNum]) // are people waiting to go down from here?
{
//if ((1.0 - this.loadFactor()) * 10.0 - wishListDown[floorNum] > 0) // assume capacity for 10 people with regular weight
// delete wishListDown[floorNum]; // mark as visited
this.destinationQueue.unshift(floorNum); // add as immediate next destination
this.checkDestinationQueue(); // announce modification
}
break;
case 0: // final destination
default:
break;
}
}
});

elevator.on("stopped_at_floor", function(floorNum) // one destination reached
{
processWishList();
updateIndicators(this); // next direction
});
}

for (var i = 0, l = floors.length; i < l; i++)
{
var floor = floors[i];
// API: floorNum()

floor.on("up_button_pressed", function() // somebody wants to go up from a certain floor
{
// elevators are choosing their next best destination,
// we just enqueue this into the global wish list queue:
var f = this.floorNum();
if (wishListUp[f])
wishListUp[f]++;
else
wishListUp[f] = 1;
processWishList();
});

floor.on("down_button_pressed", function() // somebody wants to go down from a certain floor
{
// elevators are choosing their next best destination,
// we just enqueue this into the global wish list queue:
var f = this.floorNum();
if (wishListDown[f])
wishListDown[f]++;
else
wishListDown[f] = 1;
processWishList();
});
}

function processWishList() // give idle elevators a new destination
{
for (var i = 0, l = elevators.length; i < l; i++) // idle
{
var elevator = elevators[i];
if (elevator.destinationQueue.length == 0)
{
var next = chooseFloor(elevator.currentFloor(), true); // find closest wish
if (elevator.currentFloor() != next)
elevator.goToFloor(next);
}
}
}

function getDirection(elevator)
{
if (elevator.destinationQueue.length == 0)
return 0; // nowhere
else if (elevator.currentFloor() < elevator.destinationQueue[0])
return 1; // up
else
return -1; // down
}

function chooseFloor(currentFloor, dequeue)
{
// choose next destination from the global wish lists for up and down,
// depending on a) closest distance and b) number of waiting passengers:
var wishList = {}; // joined up and down lists with passenger counts
var floors = []; // array of distinct floor numbers
for (var i in wishListUp)
{
wishList[i] = wishListUp[i];
floors.push(i);
}
for (var i in wishListDown)
if (wishList[i])
wishList[i] += wishListDown[i];
else
{
wishList[i] = wishListDown[i];
floors.push(i);
}
floors.sort(function(a, b)
{
var res = Math.abs(currentFloor - a) - Math.abs(currentFloor - b); // by closeness asc
if (res == 0)
res = wishList[b] - wishList[a]; // by passengers waiting desc
return res;
});
if (floors.length == 0)
return 0; // nothing to do, go back to base
var next = floors[0];
if (dequeue)
{
if (wishListUp[next])
delete wishListUp[next];
if (wishListDown[next])
delete wishListDown[next];
}
return next;
}

function updateIndicators(elevator)
{
return; // there seems to be a bug if announcing, people do not react ..
switch (getDirection(elevator))
{
case 1: // up
if (!elevator.goingUpIndicator())
elevator.goingUpIndicator(true);
if (elevator.goingDownIndicator())
elevator.goingDownIndicator(false);
break;

case -1: // down
if (elevator.goingUpIndicator())
elevator.goingUpIndicator(false);
if (!elevator.goingDownIndicator())
elevator.goingDownIndicator(true);
break;

case 0: // nowhere
default:
if (elevator.goingUpIndicator())
elevator.goingUpIndicator(false);
if (elevator.goingDownIndicator())
elevator.goingDownIndicator(false);
break;
}
}
},

update: function(time, elevators, floors) // loop during operation, called each frame
{
},

vendor: 'frevd'
}