IsDouble (code fragment)

        private bool IsDouble(string st)
        {
            st = st.Replace('.', separator);
            st = st.Replace(',', separator);
            NumberFormatInfo format = new NumberFormatInfo();
            format.NumberDecimalSeparator = separator.ToString();

            try
            {
                double d = Convert.ToDouble(st, format);
                return true;
            }
            catch
            {
                return false;
            }
        }