how to do a Cumulative sum by row?

ahmedltayib

i have 2 fields that is debit ,credit i want to display it with 3rd field balance that is =sum(debit-credit)
e.g.

debit credit balance
500 0 500
0 150 350
200 0 550
0 600 -50
how can i do that?

gordk

in the third memothird memo
[(<datsetname."fieldname"> - <datsetname."fieldname">)]