Removing the marker by dragging it out of the map.

Question

Hello, I have some issue here connected to removing the marker, when I'm just dragging it out of the map.

Here what do I have:

google.maps.event.addListener(marker, 'drag', function(event) {
  google.maps.event.addListenerOnce(map, 'mouseout', function(event) {
     marker.setMap(null);
  });
});

I don't know why, but it doesn't work... maybe somebody have any suggestion, how to make it work?

Thank you very much.