OpenBrowserWindow( "about:blank" );
navWin->Focus();
void nsNativeAppSupportWin::ActivateLastWindow() {    nsCOMPtr<nsIWindowMediator> med( do_GetService( kWindowMediatorCID ) );    if ( med ) {        // Get most recently used Nav window.        nsCOMPtr<nsIDOMWindowInternal> navWin;        med->GetMostRecentWindow( NS_LITERAL_STRING("navigator:browser").get(), getter_AddRefs( navWin ) );        if ( navWin ) {            // Activate that window.            HWND hwnd = hwndForDOMWindow( navWin );            if ( hwnd ) {                // Restore the window in case it is minimized.                ::ShowWindow( hwnd, SW_RESTORE );                // Use the OS call, if possible.                ::SetForegroundWindow( hwnd );            } else {                // Use internal method.                navWin->Focus();            }        } else {            // Need to create a Navigator window, then.            OpenBrowserWindow( "about:blank" );        }    }}