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,...