Message when Invoice vendor is different from PO vendor
I want to make a control in MIRO when the vendor was
different from the PO vendor.
I change to Error message in tx OMRM (Message M8 286), but this control works when the vendor is entered (in Details, Inv. Party) before making reference to the PO. If the user enters first the PO number and soon it changes the vendor, the control by means of this message does not work.
I have also dealt with the messages M8 220, 288, 291, nevertheless, no works.
Somebody knows like making this control?
thanks in advance.