InvalidValueError: setPosition: not a LatLng or LatLngLiteral: in property lat: not a number

Error message:InvalidValueError: setPosition: not a LatLng or LatLngLiteral: in property lat: not a number

Whats wrong with my code?

here my code:

function AddDriver(data) {

            var places = { lat: data.val().lat, lng: data.val().lng };

            var marker = new google.maps.Marker({
                position: places,
                map: map
            });
            markers[data.key] = marker; // add marker in the markers array...
            document.getElementById("loc").innerHTML = loc_count;


        }