public string GetCurrencyInWords(string amount) { var val = amount.Replace(" ", "").Replace(",", "."); if (val.Count(a => a == '.') > 1 || !decimal.TryParse(val, out decimal result)) { return("Invalid Amount"); } if (double.Parse(val) > 999999999.99 || double.Parse(val) < 0) { return("Please enter a valid Amount between 0 and 999 999 999,99"); } return(Currency.AmountInWords(decimal.Parse(val)).Replace(" ", " ")); }