public void replacePast() {
		DatastoreService datastore = DatastoreServiceFactory
				.getDatastoreService();
		Entity past_string = null;
		try {
			past_string = datastore.get(KeyFactory.createKey("past_string",
					"onlyOne"));
		} catch (EntityNotFoundException e) {
		}
		String[] string_box = ((Text) past_string.getProperty("text"))
				.getValue().split(",");
		StringBuilder sb = new StringBuilder();
		Pattern p = Pattern.compile("　");
		for (int i = 0; i * 4 + 4 < string_box.length; i++) {
			if (p.matcher(string_box[i * 4 + 1]).find()
					|| p.matcher(string_box[i * 4 + 2]).find())
				continue;
			sb.append("," + string_box[i * 4 + 1])
					.append("," + string_box[i * 4 + 2])
					.append("," + string_box[i * 4 + 3])
					.append("," + string_box[i * 4 + 4]);
		}
		past_string.setProperty("text", new Text(new String(sb)));
		if(false)datastore.put(past_string);
	}