Purchase Order systems usually consist of multiple tables.
Vendor table - Vendors you purchase from
Product Table - Items you purchase from the vendors
PO Header Table - Information about the PO (vendor, date, PO Number, etc)
PO Detail Table - Line items related to a specific PO.
So, to print a PO, you need to create a report. For the report's record
source (the data the report will present), you need to create a query that
joins the tables so you have all the data you need. You will probably want
to use Sorting and Grouping and Group on the PO Number. Put the PO
information in the PO group header. The line item detail should go in the
report detail section. The PO total pluse any additional items such as tax,
shipping, etc should go in the PO group footer.
When you run the report, you can use the Where argument of the OpenReport
method to tell the report which PO's to print. Using this method, you could
print one PO, all POs for a vendor, or however you want to print them.