01.
02. Dim i As Integer = 0
03. For i = 0 To DataGridView1.Rows.Count - 1
04. Dim temp_VacID As String = ""
05. temp_VacID = DataGridView1.Rows(i).Cells(i).Value
06. If tb_vTypeID.Text = temp_VacID Then
07. MessageBox.Show("คุณเลือกรหัสวัคซีนซ้ำกรุณาเลือกใหม่", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
08. bt_searchVaccine.Focus()
09. tb_vTypeID.Clear()
10. tb_vTypeName.Clear()
11. tb_qty.Clear()
12. Exit Sub
13. End If
14. Next
15. DataGridView1.Rows.Add(New String() {tb_vTypeID.Text, tb_vTypeName.Text, tb_qty.Text})
