title: Add real time data to chart control graph and switch between 2 graphs via combobox
body: <p>I have application that received real time data and show this data on my chart control graph with timer:</p>
  
  <pre><code>MyObject obj = null;
  Series seriesTraffic = null:
  
  private void LoadGraph()
  {
      seriesTraffic = new Series();
      seriesTraffic.Color = Color.Blue;
      seriesTraffic.ChartType = SeriesChartType.Spline;
      seriesTraffic.BorderWidth = 2;
      chart1.Series.Add(seriesTraffic);
      chart1.ChartAreas[0].AxisX.MajorGrid.LineColor = Color.White;
      chart1.ChartAreas[0].AxisY.MajorGrid.LineColor = Color.White;
      chart1.ChartAreas[0].AxisX.LabelStyle.Enabled = false;
      chart1.ChartAreas[0].AxisY.LabelStyle.Enabled = false;
      chart1.ChartAreas[0].AxisX.IsStartedFromZero = true;
      chart1.ChartAreas[0].AxisX.IntervalOffsetType = DateTimeIntervalType.Number;
  }
  
  private void chartTimer_Tick(object sender, EventArgs e)
  {
          var timer = (System.Windows.Forms.Timer)sender;
          MyObject wf2 = (MyObject)timer.Tag;
  lblChartMbitSec.Text = string.Format("{0} Mbit/sec", (wf2.BitsPerSecond * 0.000001).ToString("0.##"));
  
      if (seriesTraffic.Points.Count() &gt; 150)
          seriesTraffic.Points.RemoveAt(0);
      seriesTraffic.Points.Add(wf.BitsPerSecond * 0.000001);
      chart1.ResetAutoValues();
  }
  </code></pre>
  
  <p>My object contain 2 <code>properties</code> that i want my graph to show seperate:</p>
  
  <ol>
  <li>obj.BitsPerSecond</li>
  <li>obj.PacketsPerSecond</li>
  </ol>
  
  <p>Tnis is my <code>Combobox SelectedIndexChanged event</code>:</p>
  
  <pre><code>private void cbStatistics_SelectedIndexChanged(object sender, EventArgs e)
  {
              if (cbStatistics.SelectedIndex == 0)
              timerChart.Tag = wf;
          else if (cbStatistics.SelectedIndex == 1)
              timerChart.Tag = wf;
  }
  </code></pre>
  
  <p>When this selected index changed fired up i want to show my other graph, how can i do that ?</p>