private String getResponseLine(int code) {
		String res = null;
		switch(code){
		case 200:
			res = "HTTP/" + http_version + " 200 OK\r\n";
			break;
		case 401:
			res = "HTTP/" + http_version + " 401 Unauthorized\r\n";
			break;
		case 404:
			res = "HTTP/" + http_version + " 404 Not Found\r\n";
			break;
		case 403:
			res = "HTTP/" + http_version + " 403 Forbidden\r\n";
			break;
		case 206:
			res = "HTTP/" + http_version + " 206 Partial Content\r\n";
			break;
		case 304:
			res = "HTTP/" + http_version + " 304 Not Modified\r\n";
			break;
		case 400:
			res = "HTTP/" + http_version + " 400 Bad Request\r\n";
			break;
		}
		return res;
	}