subquery problem

[gaurav_sting]

hi,

please help me knowing that how do i execute a sub-query in mysql, i am not able to execute a sub-query in mysql. the query is as follows:

SELECT distinct(sub_id)
FROM cards
WHERE sub_id NOT
IN ( SELECT DISTINCT (sub_id)
FROM cards
WHERE card_title
LIKE 'Business Cards'
)

plz help me in knowing how to solve the sub-query problem. Is there any other method of implementing sub-query?

Thanx alot
Gaurav.