if (aDocURL) { mURL = aDocURL; } else { mURL.SetLength(0); }
NS_ENSURE_ARG_POINTER(aDocURL); mURL = aDocURL;
NS_IMETHODIMP nsPrintOptions::SetDocURL(const PRUnichar * aDocURL){  if (aDocURL) {    mURL = aDocURL;  } else {    mURL.SetLength(0);  }  return NS_OK;}