How to remove a PO or invoice from the list of available purchases to process in the Work File

I have purchase orders and invoices flagged as assets that I don't want to create assets for.  How can I remove those as options in the Work File?

Capital Assets

Instructional

1. In the Work File program, click Process Purchases.
2. Define purchase information and click Accept.
3. Select the records you want to stop from appearing here and click Process.
4. In the Fixed Asset Work File pop-up window, click Yes, Create.
5. On the work record screen, find the work record created from the purchase and click Delete.  Deleted records cannot be re-imported through the Work File, so if a record is incorrectly deleted the asset will need to be manually created in the New Assets program.
   1. If all records within the current find-set need to be deleted, Mass Delete can be used