data report

[jojopangit]

in data report, is it possible to sum the value of a rpttextbox and rptfunction, like :

piolo ravales
san juan, manila

balance forwarded 2,000.00 ---> rpttextbox in group header
inv 1 1,000.00 ----> rpttextbox in detail section
inv 2 500.00 ---> rpttextbox in detail section

sub total 1,500.00 ----> rptfunction in group footer
grand total 3,500.00 ----> how can i do this?

thanks in advance