【求助】谁能帮我编个密码程序啊？？注释要加啊~~谢谢啦~~急啊！

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

namespace forth
{
    class Secret
    {
        public static void PassWord()
        {
        back:
            Console.WriteLine("***欢迎进入用户登陆系统***\n");

            Console.WriteLine("请输入用户名：");
            string a = Console.ReadLine();
            Console.WriteLine("请输入用户密码：");
            string b = Console.ReadLine();


            if (a == "abc" && b == "123")
            {
                Console.Clear();
                Console.WriteLine("\t输入正确！~~");
                Console.WriteLine ();
            }
            else
            {
                Console.WriteLine();
                Console.WriteLine("您输入的用户名或密码错误！~~");
                Console.WriteLine("      请重新输入！~~");
                Console.WriteLine();
                goto back;
            }


        }
    }
}