string defaultString = "A moving line";
            while (true)
            {
                int i = 0;
                if (i % 2 == 0)
                {
                    for (int a = 7; a <= 20; a++)
                    {
                        WriteTextInPosition(defaultString, a);
                        Thread.Sleep(42);
                    }
                }
                i++;
                if (i % 2 != 0)
                {
                    for (int a = 19; a > 7; a--)
                    {
                        WriteTextInPosition(defaultString, a);
                        Thread.Sleep(42);
                    }
                }
            }