private async void GetPostion()
        {
            try
            {
                var locator = CrossGeolocator.Current;
                locator.DesiredAccuracy = 50;

                var position = await locator.GetPositionAsync(10000);

                Debug.WriteLine("Position Status: {0}", position.Timestamp);
                Debug.WriteLine("Position Latitude: {0}", position.Latitude);
                Debug.WriteLine("Position Longitude: {0}", position.Longitude);

                for (int i = 0; viewModel.stops != null && i < viewModel.stops.Count; i++)
                {
                    viewModel.stops[i].stop_distance = DistanceHelper.DistanceTo(viewModel.stops[i].stop_lat
                                                                                 , viewModel.stops[i].stop_lon
                                                                                 , position.Latitude
                                                                                 , position.Longitude);
                }
            }
            catch (Exception pException)
            {
                System.Diagnostics.Debug.WriteLine("GetPostion : " + pException.Message);
            }
            finally
            {
                GC.Collect();
            }
        }