Convert decimal to currency format string

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace CurrnecyDemo
{
    class Program
    {
        static void Main(string[] args)
        {
            decimal money = 200m;
            CurrencyTranslator currencyTranslator = new CurrencyTranslator();
            string currency = currencyTranslator.TranslateCurrency(money, "Rupee", "Paisa");
        }
    }

    public class CurrencyTranslator
    {
        // Array of sting to hold the words from one to nineteen
        private string[] _arrayOfOnes = { string.Empty, "One", "Two", "Three", "Four", "Five", "Six", "Seven", "Eight", 
"Nine", "Ten", "Eleven", "Twelve", "Thirteen", "Fourteen", "Fifteen", "Sixteen", "Seventeen", "Eighteen",
"Nineteen" };
        // Array of string to hold the words of tens - 10, 20,.., 90
        private string[] _arrayOfTens = { string.Empty , "Ten", "Twenty", "Thirty", "Forty", "Fifty", "Sixty",
"Seventy", "Eighty", "Ninety"};

        // Converts the decimal to currency
        public string TranslateCurrency(decimal currencyValue, string dollarString, string centString)
{
string numericCurrency = currencyValue.ToString().Trim();
//Check for the max capacity limit of the input
if (numericCurrency.Length > 18)
return "Invalid input format";

string leftValue, decimalWord;
//Right align the charecters with padding of "0" to length the of 18 charecters
if (numericCurrency.IndexOf(".") >= 0)
{
leftValue = numericCurrency.Substring(0, numericCurrency.IndexOf(".")).PadLeft(18, Convert.ToChar("0"));
decimalWord = numericCurrency.Substring(numericCurrency.IndexOf(".") + 1).PadRight(2, Convert.ToChar("0"));
decimalWord = (decimalWord.Length > 2 ? decimalWord.Substring(0, 2) : decimalWord);
}
else
{
leftValue = numericCurrency.PadLeft(18, Convert.ToChar("0"));
decimalWord = "0";
}

string quadrillionWord, trillionWord, billionWord, millionWord, thousandWord, hundredWord;
quadrillionWord = TranslateHundreds(Convert.ToInt32(leftValue.Substring(0, 3))); // One Quadrillion - Number of zeros 15
trillionWord = TranslateHundreds(Convert.ToInt32(leftValue.Substring(3, 3))); // One Trillion - Number of zeros 12
billionWord = TranslateHundreds(Convert.ToInt32(leftValue.Substring(6, 3))); // One Billion - Number of zeros 9
millionWord = TranslateHundreds(Convert.ToInt32(leftValue.Substring(9, 3))); // One Million - Number of zeros 6
thousandWord = TranslateHundreds(Convert.ToInt32(leftValue.Substring(12, 3)));
hundredWord = TranslateHundreds(Convert.ToInt32(leftValue.Substring(15, 3)));
decimalWord = TranslateDecimal(decimalWord);

// Start building the currency
StringBuilder currencyInEnglish = new StringBuilder();
currencyInEnglish.Append((quadrillionWord.Trim() == string.Empty ? string.Empty : quadrillionWord + " Quadrillion "));
currencyInEnglish.Append((trillionWord.Trim() == string.Empty ? string.Empty : trillionWord + " Trillion "));
currencyInEnglish.Append((billionWord.Trim() == string.Empty ? string.Empty : billionWord + " Billion "));
currencyInEnglish.Append((millionWord.Trim() == string.Empty ? string.Empty : millionWord + " Million "));
currencyInEnglish.Append((thousandWord.Trim() == string.Empty ? string.Empty : thousandWord + " Thousand "));
currencyInEnglish.Append((hundredWord.Trim() == string.Empty ? string.Empty : hundredWord));

currencyInEnglish.Append(currencyInEnglish.ToString() == string.Empty ? string.Format("Zero {0}s ", dollarString) : string.Format(" {0}s", dollarString));
if (currencyInEnglish.ToString().StartsWith(string.Format("One {0}s", dollarString)))
{
currencyInEnglish.Replace(string.Format("One {0}s", dollarString), string.Format("One {0}", dollarString));
}
currencyInEnglish.Append((decimalWord == string.Empty ? string.Format(" and Zero {0}", centString) : " and " + decimalWord + string.Format(" {0}", centString)));
return currencyInEnglish.ToString();
}


        #region Private Functions


        private string TranslateHundreds(int value)
{
string result;
// If the value is less than hundred then convert it as tens
if (value <= 99)

{
result = (TranslateTens(value));
}
else
{
result = _arrayOfOnes[Convert.ToInt32(Math.Floor(Convert.ToDecimal(value / 100)))];
// Math.Floor method is used to get the largest integer from the decial value
result += " Hundred ";
// The rest of the decimal is converted into tens
if (value - Math.Floor(Convert.ToDecimal((value / 100) * 100)) == 0)
{
result += string.Empty;
}
else
{
result += string.Empty + TranslateTens(Convert.ToInt32(value - Math.Floor(Convert.ToDecimal((value / 100) * 100))));
}
}
return result;
}


        private string TranslateTens(int value)
{
string result;
// If the value is less than 20 then get the word directly from the array
if (value < 20)

{
result = _arrayOfOnes[value];
value = 0;
}
else
{
result = _arrayOfTens[(int)Math.Floor(Convert.ToDecimal(value / 10))];
value -= Convert.ToInt32(Math.Floor(Convert.ToDecimal((value / 10) * 10)));
}
result = result + (_arrayOfOnes[value].Trim() == string.Empty ? string.Empty : "-" + _arrayOfOnes[value]);
return result;
}

        // Translates the decimal part of the currency to words
        private string TranslateDecimal(string value)
        {
            string result = string.Empty;
            // Check whether the decimal part starts with a zero. Example : 12.05
            if (value != "0")
            {
                if (value.StartsWith("0"))
                {
                    result = "Zero ";
                    result += _arrayOfOnes[Convert.ToInt32(value.Substring(1, 1))];
                }
                else
                {
                    result = TranslateTens(Convert.ToInt32(value));
                }

            }
            return result;
        }
        #endregion
    }
}