nsIDOMHTMLOptionElement* option;
nsCOMPtr<nsIDOMHTMLOptionElement> option;
nsHTMLOptionCollection::IndexOf(nsIContent* aOption){  nsIDOMHTMLOptionElement* option;  if (mDirty && (nsnull != mSelect)) {    GetOptions();  }  if ((nsnull != aOption) &&    NS_SUCCEEDED(aOption->QueryInterface(kIDOMHTMLOptionElementIID, (void**)&option))) {    return mElements.IndexOf(option);  }  return -1;}