01.foreach (GridViewRow r in dgvOrder.Rows)
02. {
03. TextBox myTextBox = (TextBox)r.FindControl("txtQuantity");
04. if (IsNaturalNumber(myTextBox.Text))
05. {
06. qty = int.Parse(myTextBox.Text);
07. price = double.Parse(r.Cells[4].Text);
08.
09. total = price * qty;
10. orderPrice += total;
11.
12. r.Cells[7].Text = total.ToString("#,##0.00");
13. lblAlert.Visible = false;
14. }
15. else
16. {
17. lblAlert.Visible = true;
18. return;
19. }
20. }
