I am building an interactive price book that has check boxes next to options/features that then expand or collapse rows in tables. We have fixed prices from our factory so I created numeric fields that are read only to show our fixed price. Then I created invisible numeric fields that would populate when the feature's check box was checked and then set back to 0 when the check box is unchecked. I have tried to do a formula for summing up the invisible numeric fields (n1+n2+n3) and the sum(n1,n2,n3) and it does not give me an error in my formula or in the form syntax but it is not returning a value. The cells I am trying to add are in three different tables but I don't see how that should be a problem. Any help here would be greatly appreciated. Thanks!