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_228973_9 (no_in_series VARCHAR, original_air_date VARCHAR)

### Question ###
If the original air date is April 1, 2003, what number in the series is this episode?

### Accurate SQL ###

SELECT no_in_series FROM table_228973_9 WHERE original_air_date = "April 1, 2003"