ASP.NET

public override void VerifyRenderingInServerForm(Control control)
    {
       
    }

private string GridViewToHtml(GridView gv)
  {
      StringBuilder sb = new StringBuilder();
      StringWriter sw = new StringWriter(sb);
      HtmlTextWriter hw = new HtmlTextWriter(sw);

      gv.RenderControl(hw);
      return sb.ToString();
  }

protected void Button3_Click(object sender, EventArgs e)
  {
      //checkout

      if (txtgrandtotal.Text == "")
      {
          //click on total button
          clsdataset.ShowAlertMessage("please click addbutton");


      }
      else
      {


          SqlConnection con1 = new SqlConnection(ConfigurationManager.ConnectionStrings["InventoryConnectionString"].ConnectionString);

          string note = TextBox2.Text;
          Session["note"] = note.ToString();

          CheckBox cc; Label id; Label categorynamee; Label itemkey; Label itemkeynamee; Label currentqty; Label salesprice;
          Label quantity; Label total;
          foreach (GridViewRow rr in GridView1.Rows)
          {
              cc = (CheckBox)rr.FindControl("chk");
              id = (Label)rr.FindControl("Label2");
              categorynamee = (Label)rr.FindControl("Label3");

              itemkey = (Label)rr.FindControl("Label4");

              itemkeynamee = (Label)rr.FindControl("Label5");

              currentqty = (Label)rr.FindControl("Label6");

              salesprice = (Label)rr.FindControl("Label7");

              quantity = (Label)rr.FindControl("Label8");

              total = (Label)rr.FindControl("Label1");


              Session["Orderno"] = id.Text;
              if (cc.Checked == true && cc.Visible == true)
              {
                  //update tblorder

                  SqlCommand cmdupd = new SqlCommand("addnotesproc", con1);
                  con1.Open();
                  cmdupd.CommandType = CommandType.StoredProcedure;
                  cmdupd.Parameters.AddWithValue("@OrderNo", Convert.ToInt32(id.Text));
                  cmdupd.Parameters.AddWithValue("@Note", TextBox2.Text);
                  cmdupd.ExecuteNonQuery();

                  con1.Close();

                  //insert  TblDetails

                  SqlCommand cmptbldetails = new SqlCommand("Addorderdetails", con1);
                  cmptbldetails.CommandType = CommandType.StoredProcedure;
                  con1.Open();

                  cmptbldetails.Parameters.AddWithValue("@OrderNo",Convert.ToInt32(id.Text));
                  cmptbldetails.Parameters.AddWithValue("@CategoryNameE",categorynamee.Text);
                  cmptbldetails.Parameters.AddWithValue("@ItemKey",itemkey.Text);
                  cmptbldetails.Parameters.AddWithValue("@ItemKeyNameE",itemkeynamee.Text);


                  cmptbldetails.Parameters.AddWithValue("@CurrentQTY",currentqty.Text);
                  cmptbldetails.Parameters.AddWithValue("@SalesPrice",salesprice.Text);
                  cmptbldetails.Parameters.AddWithValue("@Quantity",quantity.Text);
                  cmptbldetails.Parameters.AddWithValue("@Total",total.Text);
                  cmptbldetails.ExecuteNonQuery();
                  con1.Close();

              }



          }



          //updating tblorder




          //upto here
          System.Net.Mail.SmtpClient smtp = new SmtpClient();
          System.Net.Mail.MailMessage msg = new MailMessage();

          MailAddress fromaddress = new MailAddress("order@xyz.net");
          msg.From = fromaddress;

          string mailto = Session["Areamanager"].ToString();

          msg.To.Add(mailto);

          msg.Subject = "your Purchase Details";

          msg.Body = "ShopId::" + Session["UserName"].ToString() + "<br><br>" + "ShopName::" + Session["sendershopname"].ToString() + "<br><br>" + "OrderNo::" + Session["Orderno"].ToString() + "<br><br>" + "OrderDate::" + DateTime.Now.ToString() + "<br><br>" + "Total::" + Session["total"].ToString() + "<br><br>" + Session["note"].ToString() + "." + "<br><br>" + GridViewToHtml(GridView1);
          msg.IsBodyHtml = true;
          smtp.Host = "localHost";
          smtp.Port = 25;
          smtp.UseDefaultCredentials = true;

          smtp.Send(msg);




          Response.Redirect("mailsend.aspx");


      }

  }

<asp:Panel ID="Panel1" runat="server" ScrollBars="Both" Height="200" Width="60%">
    <asp:GridView ID="GvBidLists" AllowSorting="true" AllowPaging="false" runat="server"
        AutoGenerateEditButton="true" DataKeyNames="ListId" EmptyDataText="No data available."
        AutoGenerateColumns="False" >
        <EditRowStyle BackColor="skyblue" />
        <HeaderStyle BackColor="LightSteelBlue" ForeColor="#0000C0" Height="20px" HorizontalAlign="Center" />
        <RowStyle Height="20px" VerticalAlign="Middle" />
        <FooterStyle BorderColor="White" Height="20px" HorizontalAlign="Center" />
        <Columns>
            <asp:BoundField HeaderText="ListId" DataField="ListId" SortExpression="ListId" />
            <asp:BoundField HeaderText="ListName" DataField="ListName" SortExpression="ListName" />
            <asp:BoundField HeaderText="ProductTypeName" DataField="ProductTypeName" SortExpression="ProductTypeName" />
            <asp:BoundField HeaderText="Size" DataField="Size" SortExpression="Size" />
        </Columns>
    </asp:GridView>
</asp:Panel>