If NO=TO-TR-S is negative, what should NO resolve to?

TP=100
TR=80
S=30
NO=?

" wrote:

Hi,

I am looking to have implement a simple inventory formula but i'm not
sure how to get it done. Do I require an IF statement? Macro?

I have 4 variables

Total Ordered = TO
Total Received = TR
Need to Order = NO
Stock = S

I need to be able to have NO = TO - TR, at the same time, if there is
a positive total in the Stock, I need NO to subtract the stock balance
(and to not give me a negative number if I have no stock) so my Need
to Order is an accurate total.