public String graphZoomInUrl(String host, String service, String dataSource) throws Exception
	{
		String url = "/cgi-bin/graph-zoomin.cgi?host=" + URLEncoder.encode(host, defaultCharset);
		if (service != null)
			url += "&service=" + URLEncoder.encode(service, defaultCharset);
		if (dataSource != null)
			url += "&dataSource=" + URLEncoder.encode(dataSource, defaultCharset);
		url += "&metadata=true";

		return url;
	}