Formula In Report

[jimbob90]

Basically I put a formula in a report for a total cost, i need this for an invoice, but when i open an invoice for a client with more than one order
the total cost adds up costs for all of the orders, i just want it to make the total cost for one order not all of them
does anybody know???
Thanks

[June7]

Options:

1. filter the report to show only the one order ID

2. create a grouping on the order ID and calculate sum in the group header or footer