Show or hide discount caption based on an expression

Hi there,

I am new to new to navision, but i was wondering why it is not default that when you print a report and you have lines without any discount that it still will write the caption. Then the customer is wondering why he didnt get discount.

I have made this on a invoice report myself, but i am not sure its the correct way.
I go into properties of report at the caption - select visibillity and the select show or hide based on expression and write this expression:

=IIf(Fields!Discount_SalesInvLine.Value <= 0, TRUE, FALSE)

Thanks in advance