FarPoint.Web.Chart.AreaSeries series1 = new FarPoint.Web.Chart.AreaSeries();
series1.SeriesName = "Series 0";
series1.Values.Add(2.0);
series1.Values.Add(4.0);
series1.Values.Add(3.0);
series1.Values.Add(5.0);

FarPoint.Web.Chart.AreaSeries series2 = new FarPoint.Web.Chart.AreaSeries();
series2.SeriesName = "Series 1";
series2.Values.Add(2.0);
series2.Values.Add(4.0);
series2.Values.Add(3.0);
series2.Values.Add(5.0);

FarPoint.Web.Chart.StackedAreaSeries series = new FarPoint.Web.Chart.StackedAreaSeries();
//Add this for 100% stacked chart
//series.Percent = true;
series.Series.Add(series1);
series.Series.Add(series2);

FarPoint.Web.Chart.YPlotArea plotArea = new FarPoint.Web.Chart.YPlotArea();
plotArea.Location = new System.Drawing.PointF(0.2f, 0.2f);
plotArea.Size = new System.Drawing.SizeF(0.6f, 0.6f);
plotArea.Series.Add(series);
     
FarPoint.Web.Chart.ChartModel model = new FarPoint.Web.Chart.ChartModel();
model.PlotAreas.Add(plotArea);

FarPoint.Web.Spread.Chart.SpreadChart chart = new FarPoint.Web.Spread.Chart.SpreadChart();
chart.Model = model;
FpSpread1.Sheets[0].Charts.Add(chart);

Dim series1 As New FarPoint.Web.Chart.AreaSeries()
series1.SeriesName = "Series 0"
series1.Values.Add(2.0)
series1.Values.Add(4.0)
series1.Values.Add(3.0)
series1.Values.Add(1.0)

Dim series2 As New FarPoint.Web.Chart.AreaSeries()
series2.SeriesName = "Series 1"
series2.Values.Add(2.0)
series2.Values.Add(4.0)
series2.Values.Add(3.0)
series2.Values.Add(4.0)

Dim series As New FarPoint.Web.Chart.StackedAreaSeries()
'Add this for 100% stacked chart
'series.Percent = True
series.Series.Add(series1)
series.Series.Add(series2)

Dim plotArea As New FarPoint.Web.Chart.YPlotArea()
plotArea.Location = New System.Drawing.PointF(0.2F, 0.2F)
plotArea.Size = New System.Drawing.SizeF(0.6F, 0.6F)
plotArea.Series.Add(series)

Dim model As New FarPoint.Web.Chart.ChartModel()
model.PlotAreas.Add(plotArea)

Dim chart As New FarPoint.Web.Spread.Chart.SpreadChart()
chart.Model = model
FpSpread1.Sheets(0).Charts.Add(chart)