Crystal Reports Complex Formula help..

Message

   Hi,

I need this kind of report...

101 UNAIDS 10   10

       ER    2          8

       ET     4          4

102  WHO   10   14

        ER 4         10

        ET  2         8

What happens is UNAIDS first gave 10 items. The donation is identified 
by 101 (incominginovoiceid). THe next 10 is the balance. Since it was 
the first donation, the balance is the same.

Then from those 10 items given, ER took 2 items. So we have 8 in store. Then ET took 4 from the 8 items. So, we have 4 in store.

Then WHO gave 10 items. Now since we had 4 items in store already [the 4
 left from UNAIDS], the balance is 14. Now from the 14, ER took 4 so we 
remain with 10. FRom this 10, ET took 2 so we end up with 8.

I have used group headers to group them as in the above and it looks 
great. My approach was to create a forumula that would sum up total 
items taken in single batch first (i.e. 4 +2=6 for first, then again 
4+2=6 for second), subtract from balance of that specific batch. So, the
 formula gave 6 for first batch which is correct. While for the second 
one it gave 6 as well which is wrong. It gave 6 because the balance is 
10, not 14.

NOw, back to my question, how can i pass the remaining items from 
previous batch to the  batch that is following? I.E. the 6 items of 
UNAIDS to the 10 newly WHO-donated items?

here is the method i tried but failed...

SHARED numberVar looper=0;

SHARED numberVar totalTaken;

SHARED numberVar pretotalTaken;

SHARED numberVar activein;

GLOBAL numberVar prein=0;

SHARED stringVar k;

WhilePrintingRecords;

if recordnumber=1 then
(

activein:={DSSMP_RPT_StockItem;1.incominginvoiceid};

prein:=0;

totalTaken:={@remainItems};
 //@remainITems is the formula that calculates total remaining items 
ToText({DSSMP_RPT_StockItem;1.originaltotal});

 //first record. so the balance is same as the exact no of items donated
)

else (
 //row contined.
if prein<>activein then (
 //if dealing with different donation
prein:=activein;

ToText({@remainItems} + {DSSMP_RPT_StockItem;1.originaltotal});

//originaltotal is the total donated for that specific donation
)

)

i kno it is a lot to ask but can u give me some insight on how to do this.