unapplied receipts script based on as on date

hi all,

does anyone have unapplied receipts script based on as on date(11i), you can share r12 script also.

I tried making script but its not working(I am non-techincal)

   select a.cash_receipt_id,

   a.receipt_number,

   CURRENCY_CODE,

   c.customer_name,

   c.customer_number,

       a.amount orginal_rec_amt,

       a.exchange_rate,

         (a.amount - (select nvl(sum(amount_Applied), 0)

                      from ar_receivable_applications_all

                     where status = 'APP'

                       and gl_date <= to_date('&ASONDATE', 'YYYY-MM-DD')

                       AND cash_receipt_id = a.cash_receipt_id)) unapplied_amt

  from AR_CASH_RECEIPTS_ALL a, ar_payment_schedules_all b,ar_customers c