private void deltaZoomBrowser(double delta)
 {
     if (!mini)
     {
         Task <double> zoomRatio = GPMBrowser.GetZoomLevelAsync();
         zoomRatio.Wait();
         double currentZoom = zoomRatio.Result;
         double newZoom     = Math.Log10(Math.Pow(10, currentZoom) * delta);
         GPMBrowser.SetZoomLevel(newZoom);
         Properties.Settings.Default.MaxiZoomLevel = newZoom;
     }
 }