/*  void RegBrowserEvent()
        *  register IE event.
        */
        protected virtual void RegBrowserEvent(InternetExplorer ie)
        {
            object isRegistered = ie.GetProperty(TestConstants.IE_ALREADY_REGISTERED);
            if (isRegistered == null)
            {
                RegDownloadEvent(ie);
                RegWin32Event(ie);
                RegDocumentCompleteEvent(ie);
                RegNavigateEvent(ie);
                RegNewWindowEvent(ie);
                RegQuitEvent(ie);
                ie.PutProperty(TestConstants.IE_ALREADY_REGISTERED, true);

                if (OnBrowserAttached != null)
                {
                    TestEventArgs e = new TestEventArgs("Browser", ie);
                    OnBrowserAttached(this, e);
                }
            }
        }