Calc a total from figures in two fields on report if one is empty/

[Guest]

I have a database with lots of projects with DISBURSEMENTS and time CHARGE
fee records assigned to them.
On the report I am trying to display the total DISBURSEMENTS and total
CHARGE then add the two amounts together to give a total amount for the job.
First part fine.
For TOTAL I am using "=[Disbursements]+[Charge]"
If both Disbursement and Charge fields have amounts to display the total
field will display.
If either Disbursement or Charge field have nothing to display then TOTAL
returns a blank.
Can anyone help?

 

[Guest]

=Nz([Disbursements],0)+Nz([Charge],0)

This is the Null to Zero function which basically says if the field is null
make it 0