how to Avoid Duplicate records in a report

Hi,

In my report I have got the following values for the same purchase order.

But, my requirement is,

1. Not to show the same duplicated Gross value not more than once.

2. Calculate the Devaiation using the total Gross - Total Invoice amount and that will give the correct figure for the actual difference.

Gross Invoice Deviation

94,000.00 12,690.00 81,310.00

94,000.00 25,380.00 68,620.00

94,000.00 24,322.50 69,677.50

94,000.00 11,750.00 82,250.00

94,000.00 11,750.00 82,250.00

94,000.00 6,345.00 87,655.00

Total 94,000.00 92,237.50 471,762.50

Please Advice on the above to get the proper reporting display like the below.

Gross Invoice Deviation

*94,000.00* 12,690.00 81,310.00

25,380.00 68,620.00

24,322.50 69,677.50

11,750.00 82,250.00

11,750.00 82,250.00

6,345.00 87,655.00

Total 94,000.00 92,237.50 1,762.50

Thanks for the help.

Regards