Could anyone help how to add the Stacked area series dynamically?

following code sample will create 3 stacked area series. I need to append additional series in button click event.

Could any one help?

xaml:

<Window x:Class="InfragisticStackedChart.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:ig="clr-namespace:Infragistics.Controls.Charts;assembly=InfragisticsWPF4.Controls.Charts.XamDataChart.v11.2"
        Title="MainWindow" Height="350" Width="525"
        Loaded="MainWindow_OnLoaded">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition/>
            <RowDefinition/>
        </Grid.RowDefinitions>
        <ig:XamDataChart Grid.Row="1" x:Name="theChart"
                                    Legend="{Binding ElementName=xmLegend}"
                         />
 
        <ig:Legend Grid.Row="0" x:Name="xmLegend" 
                            Background="White"
                            Orientation="Horizontal" />
    </Grid>
</Window>

Code:

namespace InfragisticStackedChart
{
    using System.Collections.ObjectModel;
 
    using Infragistics;
    using Infragistics.Controls.Charts;
 
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        
 
        public MainWindow()
        {
            InitializeComponent();
        }
 
        private void MainWindow_OnLoaded(object sender, RoutedEventArgs e)
        {
            GroupBy gb = new GroupBy();
            gb.GroupMemberPath = "Date";
            gb.KeyMemberPath = "Installation";
            gb.ValueMemberPath = "Emission";
 
            ObservableCollection<InstalationEmissionDateInformation> temp = TestEmissionsCollection.GetItemSource();
            gb.ItemsSource = temp;
 
            Infragistics.Controls.Charts.NumericYAxis yAxis = new NumericYAxis();
            CategoryXAxis xAxis = new CategoryXAxis();
            xAxis.ItemsSource = gb;
            // xAxis.Label = Resources["labels"] as DataTemplate;
            xAxis.Label = "{Key}";
            this.theChart.Axes.Add(xAxis);
            this.theChart.Axes.Add(yAxis);
 
            StackedAreaSeries series = new StackedAreaSeries();
 
            series.XAxis = xAxis;
            series.YAxis = yAxis;
            series.ItemsSource = gb;
            series.AutoGenerateSeries = true;
            theChart.Series.Add(series);
        }
    }
 
    public class TestEmissionsCollection
    {
 
        public static ObservableCollection<InstalationEmissionDateInformation> GetItemSource()
        {
            ObservableCollection<InstalationEmissionDateInformation> retVal = new ObservableCollection<InstalationEmissionDateInformation>();
 
            retVal.Add(new InstalationEmissionDateInformation("A", 5, "1/1/2012", 1));
            retVal.Add(new InstalationEmissionDateInformation("B", 2, "1/1/2012", 1));
            retVal.Add(new InstalationEmissionDateInformation("C", 7, "1/1/2012", 1));
 
            retVal.Add(new InstalationEmissionDateInformation("A", 6, "1/2/2012", 1));
            retVal.Add(new InstalationEmissionDateInformation("B", 3, "1/2/2012", 1));
            retVal.Add(new InstalationEmissionDateInformation("C", 8, "1/2/2012", 1));
 
            retVal.Add(new InstalationEmissionDateInformation("A", 6, "1/3/2012", 1));
            retVal.Add(new InstalationEmissionDateInformation("B", 3, "1/3/2012", 1));
            retVal.Add(new InstalationEmissionDateInformation("C", 6, "1/3/2012", 1));
 
            retVal.Add(new InstalationEmissionDateInformation("A", 4, "1/4/2012", 1));
            retVal.Add(new InstalationEmissionDateInformation("B", 3, "1/4/2012", 1));
            retVal.Add(new InstalationEmissionDateInformation("C", 7, "1/4/2012", 1));
 
            retVal.Add(new InstalationEmissionDateInformation("D", 7, "1/1/2012", 1));
            retVal.Add(new InstalationEmissionDateInformation("D", 8, "1/2/2012", 1));
            retVal.Add(new InstalationEmissionDateInformation("D", 6, "1/3/2012", 1));
            retVal.Add(new InstalationEmissionDateInformation("D", 7, "1/4/2012", 1));
 
            //retVal.Add(new InstalationEmissionDateInformation("D", 9, "1/1/2012", 1));
            //retVal.Add(new InstalationEmissionDateInformation("D", 3, "1/2/2012", 1));
            //retVal.Add(new InstalationEmissionDateInformation("D", 6, "1/4/2012", 1));
 
            return retVal;
        }
 
        public TestEmissionsCollection()
        {
 
        }
    }
 
    public class InstalationEmissionDateInformation
    {
        public string Installation { get; set; }
        public Decimal Emission { get; set; }
        public string Date { get; set; }
        public Decimal Assignation { get; set; }
 
        public InstalationEmissionDateInformation(
            string installation,
            Decimal emission,
            string date,
            Decimal assignation)
        {
            Installation = installation;
            Emission = emission;
            Date = date;
            Assignation = assignation;
        }
    }
}