Running sum calculation

[judith]

I have grouped areport by product ID and within the group do a running sum on
quantity (oquantRS). I want to test the running sum value against three
values I have at the group level

=IIf([oquantRS]>[prodTot],"NOT POSSIBLE",IIf([oquantRS]>[prodTot47],"Con
48",IIf([oquantRS]>[prodTot46],"Con 47",IIf([oquantRS]>[prodTot45],"Con
46","Con 45"))))

Why is it flaky. It seems to work for some rows but not others

Thanks

 

[KARL DEWEY]

Maybe some nulls. Try wrapping with Nz like this - Nz([prodTot46], 0)