Datediff formula on insert returning null value

I have a form with two date fields that the user will submit their requested vacation time off with. When they insert it, I am trying to say find the difference between the request_start_date and request_end_date in days MINUS any of the days they would already have off like weekends or holidays that are included in another table. Everything inserts okay, but I am getting null for the request_duration. If I put dates in quotes and run the query it comes back with the right results. If I put the dates in the form and submit it, I get Null for the request_duration.

Thank you in advnace for any help on this!

INSERTrequest(emp_id,request_submit_date, request_start_date,request_end_date,request_duration,request_notes,time_off_id)Select@.emp_id,GETDATE(),@.request_start_date,@.request_end_date, 1 +DATEDIFF(day, @.request_start_date, @.request_end_date) - (selectcount(*)from WeekEndsAndHolidayswhere DayOfWeekDatebetween @.request_start_dateand @.request_end_date),@.request_notes,@.time_off_id

Either request_start_date or request_end_date is coming across as null. Are you sure that request_duration is the only null field?|||

Motley,

Thanks for the response. It took a while to get posted and I figured it out way before it got posted. I had worked on it for about an hour before I posted this and figure it out 5 minutes after I posted it. I didn't have one of my text boxes bound correctly.