Manual Purchase Order - restrict available items by Supplier selected

Peoplesoft 9.2

Is there a way to get the item drop down list on Purchase Order to filter based on item setup, so you are only able to select items for that supplier.

Right now I can put any item on any supplier I want during PO entry. There is no system block for users making a mistake and selecting the wrong supplier item combination.

If I'm ordering Salt, that item #3 should only be available if I use Supplier #1 on the Po.

If I'm ordering Sugar, that Item #2 should only be available if I am using Supplier #3 on the PO

We do not use requisitions or catalogs currently.