System is allowing Invoice for Total Quantity of P.O

Hi,

We are creating Invoice with respect to P.O. System is allowing multiple time invoice for same P.O.

e.g we have a P.O with 3 Line item.

Mat 1 Qty 10,toal Value 100

Mat2 Qty 15, total Value 150

Mat3 Qty 20 Total value 200

When I am creating Invoice for the P.O , 1st time one invoice is created for all items.

Again I am posting the same P.O, it is allowing me to post , there is no message, only system is blocking the payment.

However, if I am going for line item let say 20 for 2nd time it is not allowing to post.

Can any body suggest the tolerance limit to use or message no. to be taken care of, for total P.O qty to total invoice qty.

Regards

Sunami

Edited by: sunami on Nov 23, 2011 2:49 PM