Table: perry_payne_episodes
Columns: series_no
title
directed_by
written_by
original_air_date
production_code

Question: When did the series number 23 air?
SQL: SELECT "original_air_date" FROM perry_payne_episodes WHERE "series_no" = 23

Question: What is the production code of "surprise, surprise"?
SQL: SELECT MAX("production_code") FROM perry_payne_episodes WHERE "title" = '"Surprise, Surprise"'

Question: What was the airdate of 21 series number?
SQL: SELECT "original_air_date" FROM perry_payne_episodes WHERE "series_no" = 21