decimal point comma regionalization issue

[Mazza]

I try to update a gridview datasource when the Databind occurs. I have 3 textboxes where I have a value (labour, Rate of exchange Euro, Rate of Exchange GBP)
in the SQL selectstatement I use these.
All works fine for UK/US settings of the browser, as soon as I have for example a German setting I believe the decimal point and the decimal comma is causing me problems to no end. Tried various options but seems to loose the battle here.
where i mulitply my sitetime with labourcost for example i get incorrect results.

Can somebody point me in the right direction here?

code is as follows:

Private Function CreateData() As SqlDataSource

        Dim conn As String = ConfigurationManager.ConnectionStrings("connstrSQS_SQL").ConnectionString

        
        Dim EurROECurrency As Double = CDbl(TxEuroROE.Text)
        Dim GBPROECurrency As Double = CDbl(TxGBPROE.Text)
        Dim UserCurrencySettings As String = ""
        Dim LabourCost As Double = CDbl(TxLabour.Text)

        Dim LC As Double = CDbl(TxLabour.Text) '10.12D
        Dim SQL As String

        ' LabourCost = String.Format(LC.ToString(System.Globalization.CultureInfo.InvariantCulture))




        Dim CurrencySetting As String = GetSQSSettingsInfo(Session("CompCode"), "LocalCurrency").ToString
        If CurrencySetting = "DEF" Then
            UserCurrencySettings = GetSQSPriceListInfo(Session("PriceList"), "Currency").ToString()
        Else
            UserCurrencySettings = CurrencySetting
        End If

        Dim selectCmnd As String = "SELECT TblWebServiceSchedule.HRS, TblRtParts.DispRef, TblRtParts.Description, TblWebServiceSchedule.Quantity, TblRtParts.SellPrice * TblWebServiceSchedule.Quantity AS Price, TblWebServiceSchedule.SiteTime, TblWebServiceSchedule.SiteTime * " & LabourCost & " AS Labour[/U][/U], CASE WHEN [Currency SellPrice] = 'EUR' THEN (TblRtParts.SellPrice * " & EurROECurrency & " * TblWebServiceSchedule.Quantity) ELSE (TblRtParts.SellPrice * " & GBPROECurrency & " * TblWebServiceSchedule.Quantity) END AS LocalPrice, '" & UserCurrencySettings & "' AS userCurrency FROM TblWebServiceSchedule INNER JOIN TblRtParts ON TblWebServiceSchedule.PartNoCode = TblRtParts.Ref WHERE (TblWebServiceSchedule.Oil LIKE '%" & ddlOil.Value & "%' OR TblWebServiceSchedule.Oil IS NULL) AND (TblWebServiceSchedule.ModelId LIKE '%" & ddlModel.Value & "%') AND (TblRtParts.LangRef LIKE '%" & ddlPriceList.Value & "%') ORDER BY TblWebServiceSchedule.HRS, TblWebServiceSchedule.PartCode"

        Return New SqlDataSource(conn, selectCmnd)

    End Function

[iam_clint]

Well there is a difference in programming between a . and a ,
If the input is going to be a decimal point you need to replace it with a ., this is fairly easy to do since you are working with a string to begin with.