FSG report should not calculate 30 percent amount if amount in negative

Hi,

We have a requirement to add one new tax Row 23 in FSG report and its calculation is to take 30% amount of Row 22. Hence, calculation is working fine as we expected but business need small change in report. If Row 22 amount in negative then system should not calculate 30% amount it should be zero in Row 23.

Row 22-Profit before Tax

Row 23-Tax

Please let me know if any possibility is there.

Positive calculation working fine.

Negative calculation having issue it should be zero if amount in negative in same report.