/// public class MonitorSample
/// {
/// static void Main()
/// {
/// RegistryMonitor monitor = new RegistryMonitor(RegistryHive.CurrentUser, "Environment");
/// monitor.RegChanged += new EventHandler(OnRegChanged);
/// monitor.Start();
///
/// while(true);
///
/// monitor.Stop();
/// }
///
/// private void OnRegChanged(object sender, EventArgs e)
/// {
/// Console.WriteLine("registry key has changed");
/// }
/// }
///
/// /// OnRegChanged is called when the specified registry key has changed. ///
////// OnError is called when an exception occurs while watching the registry. ///
///