class Program
{
    static void Main(string[] args)
    {
        PrintOddNumbersBetween(1, 99);
        Console.ReadKey();
    }

    private static void PrintOddNumbersBetween(int startNumber, int endNumber)
    {
        var oddNumbersList = string.Join(",", OddNumbers.Range(startNumber, endNumber));
        Console.WriteLine(oddNumbersList);
    }
}

static class OddNumbers
{
    public static IEnumerable<int> Range(int startValue, int endValue)
    {
        if (startValue > endValue)
        {
            throw new ArgumentOutOfRangeException("endValue", "endValue must be greater than startValue");
        }

        for (var currentValue = startValue; currentValue <= endValue; ++currentValue)
        {
            if (IsOddNumber(currentValue))
            {
                yield return currentValue;
            }
        }
    }

    private static bool IsOddNumber(int value)
    {
        return (value % 2) != 0;
    }
}