how to add different Groups Total Amount in SSRS Reports


I developed one report. In which display Invoice no’s and AmountCur based upon the check number. If there is morethan 10 invoices page will get get break and remaining invoices and AmountCur will display in next page.

So I created two Groups. In first Group 10 invoices will display and remaining will go to next page(second Group). In second Group of AmountCur column i wrote one expression like

=sum(Fields!AmountCur.Value,“Group1”) + ReportItems!textbox8.Value

Here Textbox8 is “Group1” AmountCur column

but i am not getting proper output .

Please kindly help how to add two different groups total.