NS_IMETHOD ContextMenu (nsIDOMEvent* aEvent)       { printf("preventing ContextMenu\n"); aEvent->PreventDefault(); return NS_OK; }
NS_IMETHOD ContextMenu (nsIDOMEvent* aEvent)       { aEvent->PreventDefault(); return NS_OK; }
  NS_IMETHOD ContextMenu (nsIDOMEvent* aEvent)       { printf("preventing ContextMenu\n"); aEvent->PreventDefault(); return NS_OK; }