What is the airdate when the story is listed as hugh leonard?
CREATE TABLE table_20284 (
    "Episode" real,
    "Title" text,
    "Story" text,
    "Adapted by" text,
    "Director" text,
    "Airdate" text,
    "Exists?" text
)
SELECT "Airdate" FROM table_20284 WHERE "Story" = 'Hugh Leonard'
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 is the airdate when the story is listed as hugh leonard? ### Input: CREATE TABLE table_20284 (
    "Episode" real,
    "Title" text,
    "Story" text,
    "Adapted by" text,
    "Director" text,
    "Airdate" text,
    "Exists?" text
) ### Response: SELECT "Airdate" FROM table_20284 WHERE "Story" = 'Hugh Leonard'