using System;

public class Program

{

    public static void Main()

    {

​

        string UserName = "";

        string UserPassword = "";

        bool ValidUserNameFlag = false;

        bool ValidUserPasswordFlag = false;

        bool ValidCredentials = false;

        string[] ValidUserNames = new string[]    {"user"};

        string[] ValidUserPasswords = new string[]{"pass"};

        string[] ValidUserNames2 = new string[]    {"Bob"};

        string[] ValidUserPasswords1 = new string[]{"1234"};

        string[] ValidUserNames3 = new string[]    {"Jane"};

        string[] ValidUserPasswords3 = new string[]{"!@#$"};

        do

        {

            int eachUser = 0;

            Console.WriteLine("User Name");

            UserName = Console.ReadLine();

​

            Console.WriteLine("Password");

            UserPassword = Console.ReadLine();

            do

            {

                if(UserName == ValidUserNames[eachUser])

                {

                    ValidUserNameFlag = true;

                }

​

                if(UserPassword == ValidUserPasswords[eachUser])

                {

                    ValidUserPasswordFlag = true;

                }

​

                if(ValidUserNameFlag == true && ValidUserPasswordFlag == true )

                {

                    ValidCredentials = true;

                    break;

                }                

                eachUser++;

                Console.WriteLine("eachUser = " + eachUser);

            }while(eachUser < ValidUserNames.Length);

            if(ValidCredentials == false)

            {

                Console.WriteLine("Invalid Credentials");

            }        

        }while(!ValidCredentials);

        Console.WriteLine("Login Successful!!!");

    }

}

​

​