identification division.
       program-id.    gen-indexed-mastr.
       author.        bill rogers.

      * compile and run this program to generate the indexed
      * master file which you will update with the transaction
      * file created by program gen-2.

      * you may wish to modify the "assign" clause in the environment
      * division to specify a disk and/or path location in which
      * this program will create its output.

       environment division.
       input-output section.
       file-control.
            select out-file
                   assign to 'imastr.dat'
                   organization is indexed
                   access mode is dynamic
                   record key is out-accnt-number.

       data division.
       file section.
       fd out-file
          data record is out-item.
       01 out-item.
          02 out-accnt-number       pic x(5).
          02 out-customer-name      pic x(25).
          02 out-balance            pic s9(8)v99.

       working-storage section.

       01 data-text.
          02 pic x(40) value '00001Leo Veenstra             0000500000'.
          02 pic x(40) value '00002Wilbur Uecker            0001000000'.
          02 pic x(40) value '00003Baxter Stevens           0007500000'.
          02 pic x(40) value '00004Chuck Tascone            0000100000'.
          02 pic x(40) value '00005Mary Rice                0000250000'.
          02 pic x(40) value '00006J.C. Hasper              0000155000'.

       01 data-table redefines data-text.
          02 data-item occurs 6 times.
             03 data-accnt-number   pic 9(5).
             03 data-customer-name  pic x(25).
             03 data-balance        pic s9(8)v99.

       01 x pic 9(4) comp.

       procedure division.
       mainline.
           open output out-file.
           perform the-loop
                   varying x from 1 by 1 until x > 6.
           close out-file.
           stop run.

       the-loop.
           move data-accnt-number (x) to out-accnt-number.
           move data-customer-name (x) to out-customer-name.
           move data-balance (x) to out-balance.
           write out-item
                 invalid key display 'unexpected error'.