string defaultString = "A moving line";
            int i = 0;
            int a = 0;
            while (true)
            {
                if (i % 2 == 0 && a < 10)
                {

                    WriteTextInPosition(defaultString, a);
                    Thread.Sleep(50);
                    a++;

                }
                if (a == 9)
                    i++;
                if (a == 0 && i % 2 != 0)
                    i--;

                if (i % 2 != 0 && a > 0)
                {
                    a--;
                    WriteTextInPosition(defaultString, a);
                    Thread.Sleep(50);
                }
            }