static void Main(string[] args)
        {
            string _countStart;
            string _countEnd;
            string _oddEven;
            int _iStart;
            int _iEnd;
 
            string _runAgain = "y";
 
            while (_runAgain.ToLower().StartsWith("y"))
            {
                Console.Write("Where do you want to start counting <integer> 0>:");
                _countStart = Console.ReadLine();
                Console.Write("Where do you want to end counting <integer> 0>:");
                _countEnd = Console.ReadLine();
                Console.Write("Display even or odd numbers <e, o>:");
                _oddEven = Console.ReadLine().Substring(0,1).ToLower();
 
                if (
                    Int32.TryParse(_countStart, out _iStart)
                    && Int32.TryParse(_countEnd, out _iEnd)
                    && "e,o".Contains(_oddEven)
                    )
                {
 
                    //gives the location of decimal and hex
                    Console.WriteLine("{0} {1,20}", "Decimal", "Hex");
                    for (int i = _iStart; i < _iEnd; i++)
                    {
                        if (_oddEven == "e")
                            if (i % 2 == 0)
                                Console.WriteLine("{0} {1,23}"
                                    , i.ToString().PadLeft(3,'0')
                                    , i.ToString("x").ToUpper().PadLeft(2,'0'));
                        else
                            Console.WriteLine("{0} {1,23}"
                                , i.ToString().PadLeft(3, '0')
                                , i.ToString("x").ToUpper().PadLeft(2, '0'));
                    }
                }
                else
                {
                    Console.WriteLine("Invalid Entry detected");
                }
 
                //ask the customer do they want to run the program again
                Console.Write("Run again <yes/no>:");
                _runAgain = Console.ReadLine();
            }
 
        }