Manage YouTube using C# and Youtube API 1.6

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using Google.GData.Client;
using Google.GData.Extensions;
using Google.GData.YouTube;
using Google.GData.Extensions.MediaRss;
using Google.YouTube;

namespace Manager
{
    public partial class Login : Form
    {
        public Login()
        {
            InitializeComponent();
        }

        #region Login

        //insert your dev key here
        string devkey = "";
        

        public void authenticate()
        {
            YouTubeService service = new YouTubeService("Manager");
            service.setUserCredentials(textBox1.Text , maskedTextBox1.Text);

            try
            {
                service.QueryClientLoginToken();
                frmMain frm = new frmMain();
                frm.Username = textBox1.Text;
                frm.Password = maskedTextBox1.Text;
                frm.Show();
                this.Hide();
            }
            catch (System.Net.WebException e)
            {
                MessageBox.Show(e.Message );
            }
        }


        #endregion


        private void button1_Click(object sender, EventArgs e)
        {
            
            if (textBox1.Text != "" && maskedTextBox1.Text != "")
            {
                authenticate();
            }
            else { MessageBox.Show("Enter username and passsword"); }
        }

        private void Login_Load(object sender, EventArgs e)
        {
        }

        private void button2_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }
    }
}