In this action:
Replace the Amount field (10) with this:
[?Delivery Charge;;{CALCULATION TOTAL:Service Charge};OC;"5","10","15"]
(you can change the amounts in quotes to the amounts you want.Or
[?Delivery Charge;;{CALCULATION TOTAL:Service Charge};OCN;]
The first option will give you this popup:
This is the second option:
Here is post that describes what everything means:
The {CALCULATION TOTAL:Service Charge}
report, that is there to show what the current Service Charge is at, in the event you need to change the amount. Nothing will appear when setting the Service Charge for the first time setting the Service Charge.