How to display P.O. Vendor Reference in Item Transaction

How to display P.O. Vendor Reference in Item Transaction if the Reference column is “Purchase Order”?

Here’s my code I put in the main method of “InventTrans Form”. However when I execute this in the Overview Grid it gave me all duplicates in one reference only.

display VendRef vendorRef()

{

return PurchTable::find(InventTrans.TransRefId).VendorRef;

}

As you can see above table, Vendor Reference is Repeating with the same number. I need