Who wrote the episode with the production code of BN103? 
CREATE TABLE table_21304155_1 (written_by VARCHAR, production_code VARCHAR)
SELECT written_by FROM table_21304155_1 WHERE production_code = "BN103"
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_21304155_1 (written_by VARCHAR, production_code VARCHAR) Question: Who wrote the episode with the production code of BN103?  [/INST] SELECT written_by FROM table_21304155_1 WHERE production_code = "BN103" </s>