*aForceCharacterSet = mForceCharacterSet.ToNewUnicode();
*aForceCharacterSet = ToNewUnicode(mForceCharacterSet);
NS_IMETHODIMP DocumentViewerImpl::GetForceCharacterSet(PRUnichar** aForceCharacterSet){  NS_ENSURE_ARG_POINTER(aForceCharacterSet);  nsAutoString emptyStr;  if (mForceCharacterSet.Equals(emptyStr)) {    *aForceCharacterSet = nsnull;  }  else {    *aForceCharacterSet = mForceCharacterSet.ToNewUnicode();  }  return NS_OK;}