Ive got a problem with a formula in reports

[Guest_imported]

I am trying to find the formula to make a grand total of an invoice value in a report page footer.
when I use the =sum([JB_INVOICEVALUE]) formula it just prints out the last amount on the page is there a way of adding them all together?

Thanks in Advance!

 

[CTOROCK]

Did you try to put it in the report footer instead of page footer? "The greatest risk, is not taking one."