private String[] getListOption(String fieldName, int idx) {
        Item fd = getFieldItem(fieldName);
        if (fd == null)
            return null;
        PdfArray ar = fd.getMerged(0).getAsArray(PdfName.OPT);
        if (ar == null)
            return null;
        String[] ret = new String[ar.size()];
        for (int k = 0; k < ar.size(); ++k) {
            PdfObject obj = ar.getDirectObject( k );
            try {
                if (obj.isArray()) {
                    obj = ((PdfArray)obj).getDirectObject(idx);
                }
                if (obj.isString())
                    ret[k] = ((PdfString)obj).toUnicodeString();
                else
                    ret[k] = obj.toString();
            }
            catch (Exception e) {
                ret[k] = "";
            }
        }
        return ret;
    }