mPrefStyleSheet->SetDefaultNameSpaceID(kNameSpaceID_HTML);
mPrefStyleSheet->SetDefaultNameSpaceID(kNameSpaceID_XHTML);
nsresult PresShell::CreatePreferenceStyleSheet(void){  NS_ASSERTION(mPrefStyleSheet==nsnull, "prefStyleSheet already exists");  nsresult result = NS_OK;  result = nsComponentManager::CreateInstance(kCSSStyleSheetCID,nsnull,NS_GET_IID(nsICSSStyleSheet),(void**)&mPrefStyleSheet);  if (NS_SUCCEEDED(result)) {    NS_ASSERTION(mPrefStyleSheet, "null but no error");    nsCOMPtr<nsIURI> uri;    result = NS_NewURI(getter_AddRefs(uri), "about:PreferenceStyleSheet", nsnull);    if (NS_SUCCEEDED(result)) {      NS_ASSERTION(uri, "null but no error");      result = mPrefStyleSheet->Init(uri);      if (NS_SUCCEEDED(result)) {        mPrefStyleSheet->SetDefaultNameSpaceID(kNameSpaceID_HTML);        mStyleSet->InsertUserStyleSheetBefore(mPrefStyleSheet, nsnull);      }    }  } else {    result = NS_ERROR_OUT_OF_MEMORY;  }#ifdef DEBUG_attinasi  printf("CreatePrefStyleSheet completed: error=%ld\n",(long)result);#endif  return result;}