Fires when a navigation operation begins.
No return value.
The DISPID for this event is defined in exdispid.h. Use this value to identify the event handler when implementing IDispatch::Invoke.
This event is fired shortly after the DWebBrowserEvents::BeforeNavigate event or the DWebBrowserEvents2::BeforeNavigate2 event, unless the navigation is canceled. Any animation or "busy" indication that the container must display should be connected to this event.
Each DWebBrowserEvents2::DownloadBegin event has a corresponding DWebBrowserEvents2::DownloadComplete event.