title: Highlight data point in chart control
body: <p>I am building my first own graph and im getting to what i need step by step.
  But i have a small problem that i can not figure out. 
  My Line Chart shows data and when i hover with my mouse over the data points it shows the value. But there are no real points or circles on the data points in my chart and i can not seem to get them in the chart.</p>
  
  <p>Here is my chart:</p>
  
  <p><a href="https://i.stack.imgur.com/6vmwS.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/6vmwS.png" alt="My Chart"></a></p>
  
  <p>As you can see, it is not clear where the datapoints are. Can anybode please help me figure out how to get circles on those points.</p>
  
  <p>Here is my c# code:</p>
  
  <pre><code>protected void Button1_Click(object sender, EventArgs e)
      {
          con = new SqlConnection(@"Data Source=LP12;Initial Catalog=SmmsData;Integrated Security=True");
          cmd = new SqlCommand("Select DrukSensor,DateTime from SysteemSensorInfo2", con);
          da = new SqlDataAdapter(cmd);
          ds = new DataSet();
          da.Fill(ds);
          DataView source = new DataView(ds.Tables[0]);
          Chart1.DataSource = source;
          Chart1.Series[0].XValueMember = "DateTime";
          Chart1.Series[0].YValueMembers = "DrukSensor";
          Chart1.Series[0].BorderWidth = 3;
          Chart1.DataBind();
      }
  </code></pre>
  
  <p>And here is my html code:</p>
  
  <pre><code>          &lt;asp:Chart ID="Chart1" runat="server" BackSecondaryColor="0, 0, 192" Palette="Pastel" Width="1026px"&gt;
          &lt;series&gt;
              &lt;asp:Series ChartType="Line" Name="Series0" ToolTip="#VALY"&gt;
              &lt;/asp:Series&gt;
          &lt;/series&gt;
          &lt;chartareas&gt;
              &lt;asp:ChartArea Name="ChartArea1"&gt;
              &lt;/asp:ChartArea&gt;
          &lt;/chartareas&gt;
      &lt;/asp:Chart&gt;
  </code></pre>
  
  <p>Thanks in advance!</p>