<asp:ObjectDataSource ID="AgenteDataSource" runat="server" DataObjectTypeName="Reminder.Agente"
            DeleteMethod="Delete" 
            InsertMethod="Insert" 
            SelectMethod="GetDataTable" 
            TypeName="Reminder.Agente"
            OnSelecting="AgenteDataSource_OnSelecting"
            UpdateMethod="Update">
            <SelectParameters>
              <asp:Parameter Name="vId" Type="string" />
            </SelectParameters>

            <DeleteParameters>
              <asp:Parameter Name="vId" Type="String" />
            </DeleteParameters>
          </asp:ObjectDataSource>

    public void Update(Agente _A)
    {
      MySqlCommand cmd = new MySqlCommand();
      if (cnn.ConnectionString == string.Empty)
        cnn.ConnectionString = ConfigurationManager.ConnectionStrings["reminder_local"].ToString();
      cmd.Connection = cnn;
      cmd.CommandType = CommandType.StoredProcedure;
      cmd.Parameters.Add(new MySqlParameter("P_ID", _A.ID));
      cmd.Parameters.Add(new MySqlParameter("P_login", _A.Login));
      cmd.Parameters.Add(new MySqlParameter("P_nome", _A.Nome));
      cmd.Parameters.Add(new MySqlParameter("P_cognome", _A.Cognome));
      cmd.Parameters.Add(new MySqlParameter("P_telefono", _A.Telefono));
      cmd.Parameters.Add(new MySqlParameter("P_annullato", _A.Annullato));
      cmd.CommandText = "spUpdateAgente";

      try
      {
        if (cnn.State == ConnectionState.Closed)
          cnn.Open();
        cmd.ExecuteNonQuery();
        cnn.Close();
      }
      catch (MySqlException Exception)
      { }
    }