my database:
PRODUCT ORDER
======= =========
ID_PRODUCT ID_ORDER
NAME ID_PRODUCT
P_QTY O_QTY
how to calculate the QTY?
In ORDER form i have txtO_QTY, and btnSUBMIT,
if i submit the button, the P_QTY on PRODUCT table will decreased depends on the value of O_QTY.
thx in advance