user: Question: What is the series # on airdate September 21, 2002?
Columns: ['Season #', 'Series #', 'Episode title', 'Original air date', 'Nick prod. #']
Types: ['real', 'real', 'text', 'text', 'text']
Sample row: [1.0, 123.0, '" B2K "', 'September 21, 2002', '827']
SQL:

assistant: SELECT "Series #" FROM "Table" WHERE "Original air date" = 'September 21, 2002';