if ((nsnull != aOption) && NS_SUCCEEDED(aOption->QueryInterface(kIDOMHTMLOptionElementIID, getter_AddRefs(option)))) { return mElements.IndexOf(option); } return -1; }
  NS_IMETHOD IndexOf(nsIContent* aPossibleChild, PRInt32& aResult) const {    return mInner.IndexOf(aPossibleChild, aResult);  }