Need SAP Crystal Report formula for Blance Quantity

Question

Hi,
     i really need a formula for SAP Crytal report my requirement is
    i have group 2 Groups  one on sale order and another one on Invoice
   Example:
        ================================================================
          Order No:100001 
         Order Quantity:1000
      =================================================================
      Detail Area invoice group
      INV#        INVQty   CreditNoQty        Balance
     10002       100               0                       900
     10003        500             100                    500   
       i need formula for balance quantity . the balance quantity subtract from order quantity and plus with credit note quantity.

Answer 1

Try this:
1) Modify the code above to:
Whileprintingrecords;
Numbervar x := x +1;
If x = 1 then
Numbervar t := ({Order qty} - Invqty) + {Credit};
Else
t := ({Order qty} - t) + {credit}
2) Create a reset formula and place this on the group header 1:
Whileprintingrecords;
Numbervar x := 0;
Numbervar t := 0;
-Abhilash