What country did Gil play against on 21 23 september 2007?
CREATE TABLE table_18042031_16 (
    against VARCHAR,
    date VARCHAR
)
SELECT against FROM table_18042031_16 WHERE date = "21–23 September 2007"
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 country did Gil play against on 21 23 september 2007? ### Input: CREATE TABLE table_18042031_16 (
    against VARCHAR,
    date VARCHAR
) ### Response: SELECT against FROM table_18042031_16 WHERE date = "21–23 September 2007"