Spiral Matrix

using System;

namespace Additional_NON_Required_Advanced_Problem_Spiral_Matrix
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.Write("Enter a number: ");
            byte n = byte.Parse(Console.ReadLine());

            int[,] matrix = new int[n, n];
            sbyte row = 0;
            sbyte col = -1;
            string direction = "right";

            Console.WriteLine();
            for (int i = 1; i <= n * n; i++)
            {
                if (direction == "right")
                {
                    if (matrix[row, ++col] == 0)
                    {
                        matrix[row, col] = i;
                    }

                    if (col + 1 >= n || matrix[row, col + 1] != 0)
                    {
                        direction = "down";
                    }
                }

                else if (direction == "down")
                {
                    if (matrix[++row, col] == 0)
                    {
                        matrix[row, col] = i;
                    }
                    if (row + 1 >= n || matrix[row + 1, col] != 0)
                    {
                        direction = "left";
                    }
                }

                else if (direction == "left")
                {
                    if (matrix[row, --col] == 0)
                    {
                        matrix[row, col] = i;
                    }
                    if (col - 1 < 0 || matrix[row, col - 1] != 0)
                    {
                        direction = "up";
                    }
                }

                else if (direction == "up")
                {
                    if (matrix[--row, col] == 0)
                    {
                        matrix[row, col] = i;
                    }
                    if (row - 1 < 0 || matrix[row - 1, col] != 0)
                    {
                        direction = "right";
                    }

                }
            }

            for (int i = 0; i < matrix.GetLength(0); i++)
            {
                for (int j = 0; j < matrix.GetLength(1); j++)
                {
                    Console.Write("{0,4}", matrix[i, j] + " ");
                }

                Console.WriteLine();
            }
        }
    }
}