CREATE TABLE table_27236 ("No." FLOAT, "#" FLOAT, "Title" CLOB, "Directed by" CLOB, "Written by" CLOB, "Original air date" CLOB, "Production code" CLOB, "U.S. viewers  ( million ) " CLOB)

What is the production code of the episode written by Cathryn Humphris?
SELECT "Production code" FROM table_27236 WHERE "Written by" = 'Cathryn Humphris'
SELECT "Production code" FROM "table_27236" WHERE "Written by" = 'Cathryn Humphris'