Terminate a control input

   
 
using System;

public class MainClass {
    static void Main() {
        string resp;
        Console.WriteLine("Enter command ('x' to end):");
        while ((resp = (Console.ReadLine()).ToLower()) != "x") {
            switch (resp) {
                case "a":
                    Console.WriteLine("Doing Task A");
                    break;
                case "b":
                    Console.WriteLine("Doing Task B");
                    break;
                default:
                    Console.WriteLine("Bad choice");

                    break;
            }
        }
    }
}