Subcontracting with Multiple Purchase Orders

Toddy_Boy

When the subcontracting worksheet is run it creates one purchase order. When it is run a second time, I was hoping to create a second purchase order, this would allow us to send items to a subcontractor on a monthly basis and they be aware the stuff is coming in advance. Sadly Nav 2013 will not allow me to create a purchase order or add lines to the current order for more than one drop?

Regards