Formula to calculate money due

I have a spreadsheet with a column that I want to show how much money is still due from todays date to the completion of the job.

Each job has it's own sheet with the future weeks payments and completion date.

So if job 1 started on 03/01/2011 and finished on 28/01/2011 I would need the amount from today (19/01/2011) to the end. Maybe it would be done as the total minus any money received from the start (03/01/2011 - today)? Or just add the amounts from today to the end?

I've attached the workbook to help make sense.

Thanks