Type Ahead Data Link with Parameters


I am working on a for to raise a PO Requisition. I have a list of possible vendors and if one is selected then I want to offer a list of previously ordered parts from the vendor. If I use a Dropdown Datalink I can pass in the selected vendor num to restrict the list of parts to the selected Vendor. The problem here is it then leaves me unable to enter a new part number as it only allows parts to be selected from the list.

A type ahead Dropdown list allows me to enter free text but I cannot filter by Vendor. I am sure there must be a way around this. How can I filter a type ahead data list based on another form value? If anyone has any ideas then they would be gratefully received :smiley: