Inventory Ageing Buckets are giving negative values

Hi All,

I have developed an inventory ageing report where Ageing Buckets are showing negative values...If I add those bucket values those are matching my total quantities... Please find the attached screen below

in above image I have calculated 0-7 quantity based on below values.

            RECEIPT TOTAL STOCK restricted by POSTING DATE

           ISSUING TOTAL STOCK  restricted by POSTING DATE

then

               0-7 quantity = (RECEIPT TOTAL STOCK - ISSUING TOTAL STOCK)

Now I do not want want those negative values in my report. I need to display only those positive values if I add them those values should be equal to my total Quantity.

Please help me on this....

Regards,

G S Ramanjaneyulu.