/**
  * Read the document
  *
  * @param filename the configuration file
  */
 public void readDocument(String filename) {
   try {
     DocumentBuilderFactory factory = ScilabDocumentBuilderFactory.newInstance();
     doc = factory.newDocumentBuilder().parse(new File(filename));
   } catch (ParserConfigurationException e) {
     System.err.println(ERROR_READ + filename);
   } catch (SAXException e) {
     System.err.println(ERROR_READ + filename);
   } catch (IOException e) {
     System.err.println(ERROR_READ + filename);
   }
 }