Dragon Realms

using System;
using System.Collections.Generic;
using System.Text;

namespace DragonRealm
{
    class Program
    {
        static void displayIntro()
        {
            Console.WriteLine("You are in a land full of dragons. In front of you,");
            Console.WriteLine("you see two caves. In one cave, the dragon is friendly");
            Console.WriteLine("and will share his treasure with you. The other dragon");
            Console.WriteLine("is greedy and hungry, and will eat you on sight.");
            Console.WriteLine();
        }

        static string chooseCave()
        {
            string cave = "";
            while ((cave != "1") & (cave != "2"))
            {
                Console.WriteLine("Which cave will you go into? (1 or 2)");
                cave = Console.ReadLine();
            }
            return cave;
        }

        static void checkCave(string chosenCave)
        {
            Console.WriteLine("You approach the cave...");
            Console.WriteLine("");
            System.Threading.Thread.Sleep(800);
            Console.WriteLine("It is dark and spooky...");
            Console.WriteLine("");
            System.Threading.Thread.Sleep(800);
            Console.WriteLine("A large dragon jumps out infront of you! He opens his jaws and...");
            Console.WriteLine("");
            System.Threading.Thread.Sleep(1200);

            Random random = new Random();
            string friendlyCave = random.Next(1, 3).ToString();

            if (chosenCave == friendlyCave)
            {
                Console.WriteLine("Gives you his treasure!");
            }
            else
            {
                Console.WriteLine("Gobbles you down in one bite!");
            }
        }

        static void Main(string[] args)
        {
            string playAgain = "yes";
            while (playAgain == "yes")
            {
                Console.Clear();
                displayIntro();
                string CaveNumber = chooseCave();
                checkCave(CaveNumber);

                Console.WriteLine("Do you want to play again? (yes or no)");

                playAgain = Console.ReadLine();
            }
        }
    }
}