HTML Button Event Listener for System.Windows.Forms.WebBrowser

Program.cs

namespace ConsoleApplication1
{
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Windows.Forms;

    public class Program
    {
        private WebBrowser browser;

        private bool isAttached;

        [STAThread]
        public static int Main(string[] args)
        {
            var returnCode = 0;

            try
            {
                Console.WriteLine("Running...");
                new Program().Run();
            }
            catch (Exception ex)
            {
                Console.BackgroundColor = ConsoleColor.Red;
                Console.WriteLine("Error: " + ex.Message);
                returnCode = -1;
            }

            Console.ReadLine();

            return returnCode;
        }

        public void Run()
        {
            Form form = null;

            try
            {
                form = new Form
                {
                    Text = "Web Browser Events",
                    WindowState = FormWindowState.Maximized
                };

                var panel = new Panel
                {
                    Dock = DockStyle.Bottom,
                    Height = 400
                };

                this.browser = new WebBrowser
                {
                    Dock = DockStyle.Fill,
                    Url = new Uri("http://checkin.usairways.com")
                };

                panel.Controls.Add(this.browser);

                form.Controls.Add(panel);

                var btnAttachBrowserEvent = new Button
                {
                    Text = "Click to attach browser event...",
                    Dock = DockStyle.Top
                };

                btnAttachBrowserEvent.Click += this.btnAttachBrowserEvent_Click;

                form.Controls.Add(btnAttachBrowserEvent);

                form.ShowDialog();
            }
            finally
            {
                if (form != null && !form.IsDisposed)
                {
                    form.Dispose();
                }
            }
        }

        private void btnAttachBrowserEvent_Click(object sender, EventArgs e)
        {
            if (!this.isAttached)
            {
                var btnInternalBrowserButton = this.browser.Document.GetElementById("LookupButton");

                if (btnInternalBrowserButton == null)
                {
                    MessageBox.Show("Couldn't find the internal browser button. Please ensure the page has fully loaded");
                    return;
                }

                btnInternalBrowserButton.Click += this.btnInternalBrowserButton_Click;

                this.isAttached = true;
            }

            MessageBox.Show("Please click the check-in button to see this working");
        }

        private void btnInternalBrowserButton_Click(object sender, HtmlElementEventArgs e)
        {
            MessageBox.Show("Button inside of the browser was clicked");
        }
    }
}