Help needed to create a query

[albasel]

good day everybody

I have a table which contains a patient_name, sick_type, entering_Date&time and leaving_Date&Time.

I want to do a query that when I enter a date, it shows me all the sick people at that date and how many hours that patient is sick.

For example, if patient A is entering hospital 1/15/2012 7:00 AM and leaving the hospital 1/17/2012 12:00 PM.
So, if i enter the date as 1/16/2012, it shows me that the patient A is 24 hours as a sick
and if I enter the date as 1/17/2012, it shows me that the patient A is 12 hours as a sick

Can any body help me in that>>>

Thanks

I waiting for your great respond....