WatiN observable browser

NavigationObserver.cs

public class NavigationObserver
{
	private HttpStatusCode _statusCode;
	private bool _errorOccured;

	public NavigationObserver(IE ie)
	{
		InternetExplorer internetExplorer = (InternetExplorer)ie.InternetExplorer; 
		internetExplorer.NavigateError += IeNavigateError;
		internetExplorer.NavigateComplete2 += internetExplorer_NavigateComplete2;
	}

	void internetExplorer_NavigateComplete2(object pDisp, ref object URL)
	{
		if (!_errorOccured)
		{
			_statusCode = HttpStatusCode.OK;
		}
		_errorOccured = false;
	} 

	public void ShouldHave(HttpStatusCode expectedStatusCode)
	{
		if (!_statusCode.Equals(expectedStatusCode))
		{
			Assert.Fail(string.Format(CultureInfo.InvariantCulture, "Wrong status code. Expected {0}, but was {1}", expectedStatusCode, _statusCode));
		}
	} 
	private void IeNavigateError(object pDisp, ref object URL, ref object Frame, ref object StatusCode, ref bool Cancel)
	{
		_errorOccured = true;
		_statusCode = (HttpStatusCode)StatusCode; 
	}
}

ObservableBrowser.cs

public class ObservableBrowser : IE
{
         private NavigationObserver _observer;

	public ObservableBrowser()
	{
		_observer = new NavigationObserver(this);
	}

	public void ShouldHave(HttpStatusCode expectedStatusCode)
	{
		_observer.ShouldHave(expectedStatusCode);
	}
}