nsCOMPtr<nsIContent> content; mOuter->GetContent(getter_AddRefs(content));
nsSplitterFrameInner::AddListener(nsIPresContext* aPresContext){  nsIFrame* thumbFrame = nsnull;  mOuter->FirstChild(aPresContext, nsnull,&thumbFrame);  nsCOMPtr<nsIContent> content;  mOuter->GetContent(getter_AddRefs(content));  nsCOMPtr<nsIDOMEventReceiver> reciever(do_QueryInterface(content));  reciever->AddEventListenerByIID(NS_STATIC_CAST(nsIDOMMouseListener*,this), NS_GET_IID(nsIDOMMouseListener));  reciever->AddEventListenerByIID(NS_STATIC_CAST(nsIDOMMouseMotionListener*,this), NS_GET_IID(nsIDOMMouseMotionListener));}