Currently, there are simple table on Sales System.

Orders: Order_no, Plan_no, Inv_no, Pack_no ....
OrdItems: Order_no, Item_no, Qty, ...

Well, Plan_no is the Order# to Factory.
Factory will base on this Plan_no, Item_no to give Factory Invoice to us.

The problem is, how to "save" to data from print?
After Print, user will decide it is truth or finialise version and
do manual FAX... Therefore, Computer donno it is confirmed or not.
Since Factory give us invoice every 5 days (6 in one month),
We need to ensure:

1) Actual Qty on Sales to Customer
2) Alert if Factory give Duplicate invoice on same orders in different days.

Detail Real World situation on 1)
For instance,
In Day 1, Customer #501 put Order on Product# AAA qty 100,

Orders: PR1001, PLAN201 ...
OrdItems: PR1001, AAA, 100...

Report out:
Pro-forma PR1001, AAA, 100...
Factory Plan PLAN201, AAA, 100...

In Day 3, Customer ask for raise order to qty 120,

Orders: PR1001, PLAN201 ...
OrdItems: PR1001, AAA, 120... (Revised)

Report out:
Pro-forma PR1001, AAA, 120...

Orders: PR1001, PLAN201A ... (Change Plan#)
OrdItems: PR1001, AAA, 20... (Change Qty again!!!)

Report out:
PLAN201A, AAA, 20... (Additional Orders on Factory)

After print, reverse back to 120 as waiting later Real Invoice to Cust..


User may Print many times on both Pro-forma and Plan...
How to "save" real qty: 120 on AAA into a pool call: (SumUpSales)




Next, In Day 6, Factory ask for Invoice on AAA, 50..
In Day 8, Factory Revise Invoice because some data wrong(maybe other item/price...)
In Day 11, Factory another Invoice on AAA, 70... (Mean clear the invoice)

Now, how to "subtract" the qty on the pool (SumUpSales)...
User simple print out report and quit, NO other action take..
Although there are some manual action, there will no action on sales system!
How to take action?! "save" and "subtract" on Temp Result table: SumUpSales

How to prevent duplicate add and subtract if user print more than 1 times..
For easy check, sometime user still print the wrong version out on check!
There is nearly complete SAME action on sales system....
@_@'