PO creation

Question:
Hi All,
Is it possible to control the PO line item not to allow entries with both having a material number and account assignment category?
Thanks,
Bryant
Answer:
Hi Bryant,
This can only be achieved via the setting of User Exit.
Cheers,
HT
Answer:
Hi HT!
Am not really familiar with user exits. Any idea how to do this would be greatly appreciated.
Regards,
Bryant