doc->SetTooltipElement(nsnull);
doc->SetTooltipNode(nsnull);
XULPopupListenerImpl::MouseOut(nsIDOMEvent* aMouseEvent){  // make sure we're a tooltip. if not, bail.  if ( popupType != eXULPopupType_tooltip )    return NS_OK;    if ( mTooltipTimer ) {    mTooltipTimer->Cancel();    mTooltipTimer = nsnull;  }    if ( mPopupContent ) {    mPopupContent->RemoveAttribute("menugenerated");  // hide the popup    mPopupContent->RemoveAttribute("menuactive");    mPopupContent = nsnull;  // release the popup        // clear out the tooltip node on the document    nsCOMPtr<nsIDOMNode> eventTarget;    aMouseEvent->GetTarget(getter_AddRefs(eventTarget));    nsCOMPtr<nsIDOMXULDocument> doc;    FindDocumentForNode ( eventTarget, getter_AddRefs(doc) );    if ( doc )      doc->SetTooltipElement(nsnull);  }    return NS_OK;  } // MouseOut