WinApp VB สอบถามการใช้ code html มาใช้คำนวนในโปรแกรมครับ

Private Sub SheetinSystem()
        '  Me.Close()
        Dim Codepage1 As String
        Dim URLLot As String = "http://10.17.100.111/Nap/(S(yerblpqvokozjpfx32mtp3va))/View/Module3/frm_ScanSMTPackingMany2.aspx"
        Dim client As WebClient = New WebClient()
        '   Form1.WriteOutput(client.DownloadString(URLLot.Insert(52, Form1.LotNumber.ToString)))
        If LotNumber = Nothing Then
            MsgBox("กรุณาใส่ Lot no.")
            Exit Sub
        End If
        Codepage1 = client.DownloadString(URLLot.Insert(47, LotNumber.ToString))
        Dim OccurrencesCntSht As Integer
        Dim StartCntSht As Integer
        Dim FoundCntSht As Integer
        Do
            StartCntSht = FoundCntSht + 1
            FoundCntSht = InStr(StartCntSht, Codepage1, "OK")
            If FoundCntSht = 0 Then Exit Do
            OccurrencesCntSht += 1
        Loop
        SheetinSym = Convert.ToInt32(OccurrencesCntSht.ToString)
        '  Label21.Text = SheetinSym.ToString
        If LotNumber And Quantity <> Nothing Then
            If Convert.ToInt32(Quantity.ToString) = SheetinSym Then
                Label20.Visible = True
                Label20.ForeColor = Color.Green
                Label20.Text = "สแกนครบ Lot.แล้ว = " + SheetinSym.ToString + "/" + Quantity.ToString + " Sheet"
                WriteOutput("สแกนครบ Lot " + LotNumber.ToString + " " + SheetinSym.ToString + "/" + Quantity.ToString)
                MsgBox("สแกนครบ Lot. จำนวน = " + SheetinSym.ToString + "/" + Quantity.ToString + " Sheet")
            End If
            If Convert.ToInt32(Quantity.ToString) < SheetinSym Then
                Label20.Visible = True
                Label20.ForeColor = Color.Red
                Label20.Text = "สแกนงานเกิน = " + SheetinSym.ToString + "/" + Quantity.ToString + " Sheet"
                WriteOutput("สแกนงานเกิน Lot. " + LotNumber.ToString + " " + SheetinSym.ToString + "/" + Quantity.ToString)
                MsgBox("สแกนเกินจำนวน Input = " + SheetinSym.ToString + "/" + Quantity.ToString + " Sheet")

            End If
            If Convert.ToInt32(Quantity.ToString) > SheetinSym Then
                Label20.Visible = True
                Label20.Text = "สแกนยังไม่ครบ Lot. = " + SheetinSym.ToString + "/" + Quantity.ToString + " Sheet"
                WriteOutput("สแกนยังไม่ครบ Lot " + LotNumber.ToString + " " + SheetinSym.ToString + "/" + Quantity.ToString)

            End If
        End If
    End Sub