What was the original air date of the episode written by Michelle Offen?
CREATE TABLE table_19517621_4 (
    original_airdate VARCHAR,
    written_by VARCHAR
)
SELECT original_airdate FROM table_19517621_4 WHERE written_by = "Michelle Offen"
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: What was the original air date of the episode written by Michelle Offen? ### Input: CREATE TABLE table_19517621_4 (
    original_airdate VARCHAR,
    written_by VARCHAR
) ### Response: SELECT original_airdate FROM table_19517621_4 WHERE written_by = "Michelle Offen"