private static  String monthAdd(String dateStr) {
		String result = "";
		try {
			SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
			Date dateFormat = format.parse(dateStr);
			Calendar c = Calendar.getInstance();
			c.setTime(dateFormat);
			c.add(Calendar.MONTH, 1);
			result = format.format(c.getTime());
		} catch (ParseException e) {
			e.printStackTrace();
		}
		return result ;
	}