How do I use a boolean condition to verify email (gmail) credentials?

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

namespace GmailClient
{
    class Program
    {
        static string userName = "";
        static string password = "";

        static void Main(string[] args)
        {
            int selection;
            do
            {
                selection = ShowMenu();
                if (selection == 1)
                {
                    if (LoggedIn())
                    {
                        LoggedOn();
                        if (true)
                        {
                            GetMail();
                        }
                        
                        
                        

                    }
                    else if (false)
                    {

                    }
                    
                    // Do thing 1 
                   // Gmail.getMail(userName, password);

                    
                    
                }
                else if (selection != 2)
                {
                    //Do thing 2 
                    Console.WriteLine("That is not a valid selection");
                }
               

            }
            while (selection != 2);
        }

        private static void GetMail()
        {
            throw new NotImplementedException();
        }




        public static bool LoggedIn()
        {
            // Not sure if this part works...
            if ((userName == "") || (password == ""))
            {
                return false;
            }
            else
            {

                return true;
            }

        }
        public static int ShowMenu()
        {
            Console.WriteLine("-------------Menu--------------");
            Console.WriteLine("1)      Sign into gmail        ");
            Console.WriteLine("2)   Close the application     ");
            Console.WriteLine("-------------------------------");
            Console.WriteLine("What would you like to do? (1/2)");
            int userselect = Convert.ToInt32(Console.ReadLine());

            if (userselect == 1)
            {
                
                // present with second menu 
                // Ask user to enter their Gmail addy 
                Console.WriteLine("Enter your gmail address:");
                userName = Console.ReadLine();


                // Ask for password 
                Console.WriteLine("Enter your gmail password:");
                password = Console.ReadLine();

                
                
                


                return userselect; 

            }
            else if (userselect != 2)
            {
                // Exit application Not a valid selection 
                Console.WriteLine("That is not a valid selection");
            }


            return userselect;
        }


        public static void LoggedOn()
        {
            Console.WriteLine("-------------Menu--------------");
            Console.WriteLine("1)      Sign into gmail        ");
            Console.WriteLine("2)    Check for new Mail       ");
            Console.WriteLine("3)       Send an email         ");
            Console.WriteLine("4)    Close the application    ");
            Console.WriteLine("-------------------------------");
            int userselect = Convert.ToInt32(Console.ReadLine());

            return;

            //Method for being logged on
        }


       public static void GetMail(string newmail)
       {
            // Method for getting Mail 
          Gmail.getMail(userName, password);
          
          // newmail = Gmail.getMail(Console.ReadLine));
          
       }


        public static void SendMail (string toAddy, string subject, string body)
     {
           Console.Write(Environment.NewLine + "Who would you like to send an email to?");
           toAddy = Convert.ToString (Console.ReadLine());
           Console.Write(Environment.NewLine + "Subject: ");
           subject = Convert.ToString(Console.ReadLine());
           Console.Write(Environment.NewLine + "Your Message:");
           body = Convert.ToString(Console.ReadLine());
            
            Gmail.sendMail(userName, password, toAddy, subject, body); 
        }


    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using System.Net;
using System.Net.Mail;
namespace GmailClient
{
    class Gmail
    {
        public static void sendMail(string userName, string password, string toAddy, string subject, string body)
        {
            MailAddress fromAddress = new MailAddress(userName);
            MailAddress toAddress = new MailAddress(toAddy);
            SmtpClient smtp = new SmtpClient();
            smtp.Host = "smtp.gmail.com";
            smtp.Port = 587;
            smtp.EnableSsl = true;
            smtp.DeliveryMethod = SmtpDeliveryMethod.Network;
            smtp.UseDefaultCredentials = false;
            smtp.Credentials = new NetworkCredential(fromAddress.Address, password);
            MailMessage message = new MailMessage(fromAddress, toAddress);
            message.Subject = subject;
            message.Body = body;
            smtp.Send(message);
        }
        public static string[] getMail(string userName, string password)
        {
            System.Net.WebClient objClient = new System.Net.WebClient();
            XmlNodeList nodelist;
            XmlNode node;
            string response;
            XmlDocument xmlDoc = new XmlDocument();
            Console.WriteLine("checking for mail...");
            objClient.Credentials = new System.Net.NetworkCredential(userName, password);
            response = Encoding.UTF8.GetString(objClient.DownloadData("https://mail.google.com/mail/feed/atom/"));
            response = response.Replace(@"<feed version=""0.3"" xmlns=""http://purl.org/atom/ns#"">", "<feed>");
            xmlDoc.LoadXml(response);
            node = xmlDoc.SelectSingleNode("/feed/fullcount");
            int mailCount = Convert.ToInt32(node.InnerText);
            string[] emails = new string[0];
            if (mailCount > 0)
            {
                emails = new string[mailCount];
                nodelist = xmlDoc.SelectNodes("/feed/entry");
                node = xmlDoc.SelectSingleNode("title");
                int tempCounter = 0;
                foreach (XmlNode n in nodelist)
                {
                    emails[tempCounter] = "From: " + n.ChildNodes[6].InnerText + "\nSubject: " + n.FirstChild.InnerText + "\nSummary: " + n.ChildNodes[1].InnerText;
                    tempCounter++;
                }
            }
            return emails;
        }
    }
}