System.Web.UI.DataVisualization.Charting.Chart chart = new System.Web.UI.DataVisualization.Charting.Chart();
     chart.ChartAreas.Add(CreateChartArea("LandingConfPerArrStnChartArea"));
        chart.ChartAreas["LandingConfPerArrStnChartArea"].AxisY2.Enabled = AxisEnabled.True;
        chart.ChartAreas["LandingConfPerArrStnChartArea"].AxisY2. = AxisEnabled.True;
        chart.Series.Add(CreateSeries_LandingConf3(); //This and the next series form the stacked columns
        chart.Series.Add(CreateSeries_LandingConfFull(); //This and the previous series form the stacked column
        chart.Series.Add(CreateSeries_LandingConfNoOfFlights(); //This is the Line series named "Nbr of flights" that is ties to the secondary yaxis
        chart.Series["Nbr of flights"].YAxisType = AxisType.Secondary;
        MemoryStream ms = new MemoryStream();
        chart.SaveImage(ms);
        return File(ms.GetBuffer(), @"image/png");

Series seriesDetail = new Series();

        seriesDetail.Name = "Conf 3";

        seriesDetail.IsValueShownAsLabel = false;
        seriesDetail.ChartType = SeriesChartType.StackedColumn100;
        DataPoint point;
        Models.LandingConfDetails[] landingConfArray;

        seriesDetail.ChartArea = "LandingConfPerArrStnChartArea";

        foreach (LandingConfDetails landingConf in landingConfArray)
        {
            point = new DataPoint();
            point.AxisLabel = landingConf.ArrStn;
            point.YValues = new double[] { landingConf.Conf3 };
            seriesDetail.Points.Add(point);
        }

        return seriesDetail;

Series seriesDetail = new Series();

        seriesDetail.Name = "Nbr of flights";

        seriesDetail.ChartType = SeriesChartType.Line;

        DataPoint point;

        Models.LandingConfDetails[] landingConfArray;

        landingConfArray = _landingConfPerArrStn;

        seriesDetail.ChartArea = "LandingConfPerArrStnChartArea";

        foreach (LandingConfDetails landingConf in landingConfArray)
        {
            point.AxisLabel = landingConf.ArrStn;
            point.YValues = new double[] { landingConf.Conf3 + landingConf.ConfFull };
            seriesDetail.Points.Add(point);
        }

        return seriesDetail;
    }