You're welcome. :)

>Thanks Sergey ;)
>
>>Hi Eric
>>
>>Sorry, I misread your original post. Try

>>DECLARE @IdList varchar(8000)
>>SELECT @IdList = ISNULL(@IdList + ', ', '') + StudentId
>>	FROM survey
>>	WHERE StudentId IN ( SELECT StudentId FROM survey
>>		WHERE interest IN (3,45)
>>		GROUP BY StudentId
>>		HAVING COUNT(*) = 2 )
>>GROUP BY StudentId
>>SELECT @IdList

As you can see, ther are two "variables" in this query: the list of interests '(3,45)' and number of values in the list - '2'.
>>
>>