How to Show Last Admit Date

I have a report that shows patient information, such as patient number, name, and admit date. It also has a date parameter. I enter in the date and it shows all the patients admitted that day. I would like to show the last date the patient was admitted before the date I ran the report for.

For example, if I run the report for 12/20/06, I want to see the patients that were admitted that day and their info like name, and patient number. I would also like to see the last date they were admitted.

Could you just do a subquery to get the max date for each patient from before the date parameter? Something like this:

select ...
(select max(admit_date) from patient_admittances pa where p.patient_id = pa.patient_id and admit_date < @.RunDate)
from patients p
inner join ...

Jarret