How to display Invoice amount and Sales Tax in PurchTable form which are in purchtotal form?

Hi,

Open(PurchTable Form->Inquires->Totals) where you will find Invoice amount and Sales Tax. I wanna display Invoice amount and Sales Tax in overview Tab of PurchTable form. There is no datasource in purchtotal form but EDT is specified for each and every control in design tab of PurchTotal Form. How can I display the same in overview tab of PurchTable form?

Regards,

S.Kuppusamy.