protected void addInterval(AuToBIFileReader reader)
      throws IOException, TextGridSyntaxErrorException {
    String xmin = AuToBIReaderUtils.removeTabsAndTrim(reader.readLine());
    if (xmin == null || !xmin.contains("xmin ="))
      throw new TextGridSyntaxErrorException("missing xmin at line: " + reader.getLineNumber());

    xmin = xmin.replace("xmin = ", "").trim();

    String xmax = AuToBIReaderUtils.removeTabsAndTrim(reader.readLine());
    if (xmax == null || !xmax.contains("xmax ="))
      throw new TextGridSyntaxErrorException("missing xmax at line: " + reader.getLineNumber());

    xmax = xmax.replace("xmax = ", "").trim();

    Region region = new Region(Double.valueOf(xmin), Double.valueOf(xmax));
    region.setFile(reader.getFilename());

    String text = AuToBIReaderUtils.removeTabsAndTrim(reader.readLine());
    if (text == null || !text.contains("text ="))
      throw new TextGridSyntaxErrorException("missing mark at line: " + reader.getLineNumber());

    text = text.replaceAll("text = \"(.*?)\"", "$1").trim();
    
    if(text.equals("@BG"))
        text="sil";
    region.setLabel(text);

    regions.add(region);
  }