public char comF, comR;   // to correct Comma- / point problem comF : wrong seperator
        // comR  : correct separator

        string wrongDataFormat = "wrong Data Format";


        public void ConvertToDouble(string text, ref double nb)
        {
            // Secure Conversion independant of Komma- Version of PC
            // comF contains String with wrong camma, comR contains string with correct comma
            // if number format is wrong, result is old number
            // Call :  ConvertToDouble(text,ref number);
            // removes all thousand- Seperators
            // examples: (if decimal sep =".")
            // 1000,000,000.23 --> 1000000000.23
            // 1000.000.000,23 --> 1000000000.23
            // 0.23 --> 0.23
            // 0,23 --> 0.23
            // 1000,023 --> 1000.023
            // 1000.023 --> 1000.023

            // examples: (if decimal sep =",")
            // 1000,000,000.23 --> 1000000000,23
            // 1000.000.000,23 --> 1000000000,23
            // 0.23 --> 0,23
            // 0,23 --> 0,23
            // 1000,023 --> 1000,023
            // 1000.023 --> 1000,023

            string TestText = (0.1).ToString("f1");

            if (TestText.Substring(1, 1) == ".")  // Check which is the actual Decimal separator
            { comF = ','; comR = '.'; }
            else
            { comF = '.'; comR = ','; }

            double number = 0;
            char[] seps = new char[2];
            seps[0] = ','; // both possible decimal seperators
            seps[1] = '.';
            // check if Thousand- group sign is available. If more than one sign, all left signs are removed
            int index = 0, cnt = 0;
            while (index > -1)  // count number of seperators
            {
                index = text.IndexOfAny(seps, index);  // look for next position of seps
                if (index > -1) { cnt++; index++; }
            }
            string newtext = text;
            if (cnt > 1)  // If more than one sign, all left signs are removed
            {
                string leftSign = text.Substring(text.IndexOfAny(seps), 1);  // what is the left sign?
                newtext = text.Replace(leftSign, "");// Remove all left signs
            }
            string help = newtext.Replace(comF, comR); // Change into correct decimal sep
            if (Double.TryParse(help, out number))
                nb = number;
            else MessageBox.Show(wrongDataFormat);

        }