Membuat program dengan menggunakan record, file dan procedure

uses crt;

type produk = record

     kode  : string[4];

     jumlah: integer;

     end;

var fpro  : file of produk;

    rpro  : produk;

    lg    : char;

    i,j,pil     : integer;

    nama : string[30];

    harga,total : longint;

    totB : real;

    disc: real;

procedure openproduk;

begin

     assign(fpro,'c:\produk.dat');

     {$I-}reset(fpro);

     {$I+}if Ioresult<>0 then rewrite(fpro);

end;

procedure menu;

begin

     clrscr;

     gotoxy(10,5); write('menu utama');

     gotoxy(10,6); write('_______________________');

     gotoxy(10,7); write('1. input produk');

     gotoxy(10,8); write('2. output produk');

     gotoxy(10,9); write('3. keluar');

     gotoxy(10,10); write('______________________');

     gotoxy(10,11); write('pilihan :'); readln(pil);

     end;

procedure input;

begin

     clrscr;

     openproduk;

     repeat

           gotoxy(30,5); write('Input Data Produk');

           gotoxy(30,6); write('________________________________');

           gotoxy(30,7); write('kode      :'); readln(rpro.kode);

           gotoxy(30,8); write('jumlah    :'); readln(rpro.jumlah);

           gotoxy(30,9); write('________________________________');

           gotoxy(30,10); write('input lagi[Y/T] :'); readln(lg);

           seek(fpro,filesize(fpro)); write(fpro,rpro);

           clrscr;

           until upcase(lg)='T';

           end;

procedure output;

begin

     clrscr;

     i:=1;

     openproduk;

        gotoxy(3,1); write('Informasi penjualan produk');

        gotoxy(3,2); write('________________________________________________________________________________');

        gotoxy(3,3); write('no kode  nama         harga     jumlah   totalharga  discount    TotalBayar');

        gotoxy(3,4); write('________________________________________________________________________________');

        seek(fpro,0);

        while not eof(fpro) do

        begin

             seek(fpro,i-1); read(fpro,rpro);

             if rpro.kode='T010' then

             begin

                  nama :='DVD';

                  harga:=650000;

             end

             else if rpro.kode='T011' then

             begin

                  nama :='TV Sony';

                  harga:=1000000;

             end

             else if rpro.kode='T012' then

             begin

                  nama :='TV Polytron';

                  harga:=1200000;

             end;

             total:=rpro.jumlah*harga;

             begin

                  if total>=10000000 then  disc :=total*0.10

                  else  disc :=total*0;

             end;

                  totB :=total-disc;

             gotoxy(3,4+i); write(i:2,' ',rpro.kode,' ',nama);

             gotoxy(24,4+i); write('Rp.',harga:8,' ',rpro.jumlah:3);

             gotoxy(43,4+i); write('Rp.',total);

             gotoxy(56,4+i); write('Rp.',disc:2:0);

             gotoxy(68,4+i); write('Rp.',totB:2:0);

             inc(i);

             end;

             readln;

        end;

        begin

          pil:=0;

          while pil<>3 do

          begin

          menu;

          case pil of

               1 : input;

               2 : output;

          end;

          end;

           close (fpro);

     end.