Purchase Requsition Subform Subtotal Calculation

[rgaito]

I am using Access 2013 to create a purchase requisition (PR) form. The PR has a continuous subform [sfrmPurchaseRequisitionDetails1] which has fields of [Quantity], [UnitPrice], [txtExtendedPrice] and [SubTotal]. The [txtExtendedPrice] field is a calculation of =[Quantity]*[UnitPrice] and it works fine. The subform will contain multiply records with extended prices. I am unable to calculate a total of all of the [txtExtendedPrice] field. I have tried =sum[txtExtendedPrice], =[txtExtendedPrice] without success and have been unable to locate an answer in forums. Any help provided is greatly appreciated.

[ranman256]

you can put a field in the form or subform that is
=DSUM([extPrice], "qsQuery", "[pr]=" & forms!frmPR!txtPR)

[NTC]

you must build an exterior query as R256 advises....or....... modify your table so that extended price is a field, not unbound - and write the value into that field......then you can sum it in the footer of the form object....