conversion in c#.net

/* File name : NumberToEnglish.cs */

/************************************************************************************************
 * This program is free software; you can redistribute it and/or modify.No terms and conditions!
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * Report bugs or comments to the author:Fred Byamugisha (fredbyk@gmail.com)[Kampala,Uganda]
 ***********************************************************************************************/
using System;
namespace custom.util
{
 public class NumberToEnglish
  {
   public String changeNumericToWords(double numb)
   {
    String num = numb.ToString();
    return changeToWords(num, false);
   }
   public String changeCurrencyToWords(String numb)
   {
    return changeToWords(numb, true);
   }
   public String changeNumericToWords(String numb)
   {
    return changeToWords(numb, false);
   }
   public String changeCurrencyToWords(double numb)
   {
    return changeToWords(numb.ToString(), true);
   }
   private String changeToWords(String numb, bool isCurrency)
   {
   String val = "", wholeNo = numb, points = "", andStr = "", pointStr="";
   String endStr = (isCurrency) ? ("Only") : ("");
   try
   {
    int decimalPlace = numb.IndexOf(".");
    if (decimalPlace > 0)
    {
     wholeNo = numb.Substring(0, decimalPlace);
     points = numb.Substring(decimalPlace+1);
     if (Convert.ToInt32(points) > 0)
     {
      andStr = (isCurrency)?("and"):("point");// just to separate whole numbers from points/cents
      endStr = (isCurrency) ? ("Cents "+endStr) : ("");
      pointStr = translateCents(points);
     }
    }
    val = String.Format("{0} {1}{2} {3}",translateWholeNumber(wholeNo).Trim(),andStr,pointStr,endStr);
   }
   catch { ;}
   return val;
  }
   private String translateWholeNumber(String number)
   {
    string word = "";
    try
    {
     bool beginsZero = false;//tests for 0XX
     bool isDone = false;//test if already translated
     double dblAmt = (Convert.ToDouble(number));
     //if ((dblAmt > 0) && number.StartsWith("0"))
     if (dblAmt > 0)
     {//test for zero or digit zero in a nuemric
      beginsZero = number.StartsWith("0");

      int numDigits = number.Length;
      int pos = 0;//store digit grouping
      String place = "";//digit grouping name:hundres,thousand,etc...
      switch (numDigits)
      {
       case 1://ones' range
        word = ones(number);
        isDone = true;
        break;
       case 2://tens' range
        word = tens(number);
        isDone = true;
        break;
       case 3://hundreds' range
        pos = (numDigits % 3) + 1;
        place = " Hundred ";
        break;
       case 4://thousands' range
       case 5:
       case 6:
        pos = (numDigits % 4) + 1;
        place = " Thousand ";
        break;
       case 7://millions' range
       case 8:
       case 9:
        pos = (numDigits % 7) + 1;
        place = " Million ";
        break;
       case 10://Billions's range
        pos = (numDigits % 10) + 1;
        place = " Billion ";
        break;
       //add extra case options for anything above Billion...
       default:
        isDone = true;
        break;
      }
      if (!isDone)
      {//if transalation is not done, continue...(Recursion comes in now!!)
       word = translateWholeNumber(number.Substring(0, pos)) + place + translateWholeNumber(number.Substring(pos));
       //check for trailing zeros
       if (beginsZero) word = " and " + word.Trim();
      }
      //ignore digit grouping names
      if (word.Trim().Equals(place.Trim())) word = "";
     }
    }
    catch { ;}
    return word.Trim();
   }
   private String tens(String digit)
   {
    int digt = Convert.ToInt32(digit);
    String name = null;
    switch (digt)
    {
     case 10:
      name = "Ten";
      break;
     case 11:
      name = "Eleven";
      break;
     case 12:
      name = "Twelve";
      break;
     case 13:
      name = "Thirteen";
      break;
     case 14:
      name = "Fourteen";
      break;
     case 15:
      name = "Fifteen";
      break;
     case 16:
      name = "Sixteen";
      break;
     case 17:
      name = "Seventeen";
      break;
     case 18:
      name = "Eighteen";
      break;
     case 19:
      name = "Nineteen";
      break;
     case 20:
      name = "Twenty";
      break;
     case 30:
      name = "Thirty";
      break;
     case 40:
      name = "Fourty";
      break;
     case 50:
      name = "Fifty";
      break;
     case 60:
      name = "Sixty";
      break;
     case 70:
      name = "Seventy";
      break;
     case 80:
      name = "Eighty";
      break;
     case 90:
      name = "Ninety";
      break;
     default:
      if (digt > 0)
      {
       name = tens(digit.Substring(0, 1) + "0") + " " + ones(digit.Substring(1));
      }
      break;
    }
    return name;
   }
   private String ones(String digit)
   {
    int digt = Convert.ToInt32(digit);
    String name = "";
    switch (digt)
    {
     case 1:
      name = "One";
      break;
     case 2:
      name = "Two";
      break;
     case 3:
      name = "Three";
      break;
     case 4:
      name = "Four";
      break;
     case 5:
      name = "Five";
      break;
     case 6:
      name = "Six";
      break;
     case 7:
      name = "Seven";
      break;
     case 8:
      name = "Eight";
      break;
     case 9:
      name = "Nine";
      break;
    }
    return name;
   }
   private String translateCents(String cents)
   {
    String cts = "", digit = "", engOne = "";
     for (int i = 0; i < cents.Length; i++)
     {
      digit = cents[i].ToString();
      if (digit.Equals("0"))
      {
       engOne = "Zero";
      }
      else
      {
       engOne = ones(digit);
      }
      cts += " " + engOne;
     }
    return cts;
   }
  }
 }

Main Program:

using System;
using System.Text;

namespace custom.util
{
 class Program
 {
  static void Main(string[] args)
  {
   NumberToEnglish num = new NumberToEnglish();
   while (true)
   {
    String input = Console.ReadLine();
    if (input == null || input.Length == 0) break;
    Console.WriteLine(num.changeNumericToWords(input));
    Console.WriteLine();
   }
  }
 }
}