Calculating sum of portal records

[Joe_Schmo]

How can I get a sum of all the values from all rows in a given field of a portal? I have a line items portal on an Invoice layout. I need the total of each charge in the line items to be displayed outside the portal (in the rest of the invoice) and be able to use that in another calculation.

In the attached file, it's the "Rental Cost" of the top portal that I want to add up and put into the "Rent" field in the Fee section on the right of the layout.

Rental.fp7.zip

[Ocean West]

Sum ( Line_Items::RentalCost )

FYI if you are printing this forum i would make sure that the button elements don't print by ticking this check box.

[Joe_Schmo]

Sum ( Line_Items::RentalCost )

FYI if you are printing this forum i would make sure that the button elements don't print by ticking this check box.

Some things in FM (and OSX in general) are so simple that it doesn't even occur to you that the solution could be that simple! I entered Sum ( Line_Items::RentalCost ) in the calculation for the field I wanted the total in and it worked. I thought I needed to do something different to tell FM to only total the rental costs for this invoice but I guess the relationship does that already! THANKS

And, I do plan on removing items from view when printing as you mentioned, but I haven't really started tweaking the layout yet. Still working on getting all the calculations to work. Thanks again for you help!