real time chart and databse

Question

hi beautiful people ,

i want to display real chart time , binded with Mysql databse .

Axe x shows the speed (int ) and Y shows DATETIME .

my databse get updated every second

 my load graph function is :

public void load_graph()
       {

           MySql.Data.MySqlClient.MySqlCommand cmd = new MySql.Data.MySqlClient.MySqlCommand("select * from val_api", conn);
           MySql.Data.MySqlClient.MySqlDataReader reader;
           try
           {
               conn.Open();
               reader = cmd.ExecuteReader();
               while (reader.Read())
               {
                   this.chart1.Series["Vitesse"].Points.AddXY(reader.GetInt16("vitesse"), reader.GetDateTime("dateV"));
                   this.chart1.Update();


               }
           }
           catch (Exception ex)
           {
               MessageBox.Show(this, ex.Message);
           }
           conn.Close();
       }

 i tried using this fuction with timer , but it doesn't work , a line shows up and than my app stops without throwing any exception .

can you please help