} else if (event == vtkCommand::MouseWheelBackwardEvent && !isi->GetInteractor()->GetControlKey()) {
this->SM->GetSlicer(VisibleInWindow)->SetSlice(this->SM->GetSlicer(VisibleInWindow)->GetSlice()-1);
this->SM->UpdateSlice(VisibleInWindow);
} else if (event == vtkCommand::MouseWheelBackwardEvent && !isi->GetInteractor()->GetControlKey()) {
this->SM->GetSlicer(VisibleInWindow)->SetSlice(this->SM->GetSlicer(VisibleInWindow)->GetSlice()-1);
this->SM->UpdateSlice(VisibleInWindow);