Step 2:
Go to “pay supplier invoices”

Step 3:
Select Supplier

Step 4:
Select invoices

Step 5:
Fill in either “Supplier Credits or “Payment Amt”

Step 6:
Click on pay selected.

This is just a quick guide. See below explaining more or click on this link:
http://www.smart-it.co.za/help/pay_supplier_invoices.htm