Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_13 (purpose VARCHAR, on_air_id VARCHAR)

### Question ###
Name the purpose for on-air ID of 2xx

### Accurate SQL ###

SELECT purpose FROM table_name_13 WHERE on_air_id = "2xx"