Sub GridView1_RowCommand(ByVal source As Object, ByVal e As GridViewCommandEventArgs)
If e.CommandName = "showdata" Then
Dim txtName As TextBox = CType(GridView1.FooterRow.FindControl("sale_num"), TextBox)
If Not IsNothing(txtName) Then
txtName.Text = ccc.Text ' ได้ค่า Label หรือ Textbox
End If
Response.Redirect("123.aspx")
End If