private String getBaseFileName () {
        String strLevel = null;
        String strName = null;
        String strPubDate = null;
        
        StringTokenizer st = new StringTokenizer(url.getQuery(), "&");
        while (st.hasMoreElements()) {
            String[] sa = st.nextToken().split("=");
            if (sa.length == 2) {
                if (sa[0].equals("level"))
                    strLevel = sa[1];
                else if (sa[0].equals("name"))
                    strName = sa[1];
                else if (sa[0].equals("pubdate"))
                    strPubDate = sa[1];
            }
        }
        StringBuilder sb = new StringBuilder();
        if (strLevel != null) sb.append(strLevel);
        else sb.append("UNKNOWN");
        if (strName != null) {
            sb.append("_");
            sb.append(strName);
        }
        if (strPubDate != null) {
            sb.append("_");
            sb.append(strPubDate);
        }
        else sb.append("_NODATE");
        
        return sb.toString();
    }