user: Question: What's the production code of the episode written by Kirker Butler and directed by Dan Povenmire?
Columns: ['No. in series', 'No. in season', 'Title', 'Directed by', 'Written by', 'Original air date', 'Production code']
Types: ['real', 'real', 'text', 'text', 'text', 'text', 'text']
Sample row: [81.0, 1.0, '" Stewie Loves Lois "', 'Mike Kim', 'Mark Hentemann', 'September10,2006', '4ACX32']
SQL:

assistant: SELECT "Production code" FROM "Table" WHERE "Written by" = 'Kirker Butler' AND "Directed by" = 'Dan Povenmire';