When displaying a chart is it possible to let users select a custom period for the data? 

@{
    var db = Database.Open("datab");
    var data = db.Query("SELECT Date, XAG FROM metals WHERE ID > '4000'");
    var myTheme = @"<Chart BorderlineDashStyle=""Solid"" BorderlineWidth=""1"" BorderlineColor=""#eeeeee"" BackSecondaryColor=""#ffffff"" BackColor=""#fbfbfb"" BackGradientStyle=""TopBottom"" Palette=""BrightPastel"" AntiAliasing=""All"">
  <ChartAreas>
    <ChartArea Name=""Default"" _Template_=""All"" BackColor=""Transparent"">
      <AxisY LineColor=""64, 64, 64, 64"">
        <MajorGrid Interval=""Auto"" LineColor=""#dddddd"" />
        <LabelStyle Font=""Trebuchet MS, 8.25pt"" />
      </AxisY>
      <AxisX LineColor=""64, 64, 64, 64"">
        <MajorGrid LineColor=""#dddddd"" />
        <LabelStyle Font=""Trebuchet MS, 8.25pt"" />
      </AxisX>
    </ChartArea>
  </ChartAreas>
<Legends>
   <Legend _Template_=""All"" Alignment=""Center"" BackColor=""Transparent"" Docking=""Bottom"" Font=""Trebuchet MS, 8.25pt"" IsTextAutoFit =""False"" LegendStyle=""Row""></Legend>
</Legends>
</Chart>";
    var myChart = new Chart(width:610, height:498, theme: myTheme)
    .AddTitle("XAG")
    .AddLegend()
    .AddSeries("XAG", chartType: "Line", xValue: data, xField: "Data", yValues: data, yFields: "XAG")
    .Write("png");
}