public boolean checkRoom(int room_number,String date,int period){
		boolean hasRow = false;
		String query = "select * from reservation where room_number="+room_number+" and ((start_day<='"+date+"' and start_day+period>='"+date+"')or('"+date+"'<=start_day and '"+date+"'>=start_day"+"-"+period+"))";;
//		System.out.println(query);
		Object[][] data = helper.executeSelectQuery(query);
//		System.out.println(data.length+" "+room_number+" "+data[0][1].toString());
		if(data.length>0){
			hasRow = true;
		}
		return hasRow;
	}