pie chart is not visible

Question

i have code for a pie chart but ehn i run i cant see the pie chartit showig white box when i drag the pie chart area the code is below plz help me

"Chart1" runat="server" ImageType="Jpeg">

            "Series1" ChartType="Pie" IsValueShownAsLabel="True">



            "ChartArea1">
                "True" LightStyle="Realistic" />

 and the code behind is :

 

SqlConnection con = new SqlConnection(ppd);
            SqlCommand cmd = new SqlCommand("Some query, con);


            cmd.Parameters.AddWithValue("@userid", output);
                Series series = Chart1.Series["Series1"];
                con.Open();
                SqlDataReader rdr = cmd.ExecuteReader();
                while (rdr.Read())
                {
                    series.Points.AddXY(rdr["schemeid"].ToString(), rdr["scheme"]);
                }