Работа с файлами

type
  TNameStr = String[31];
  TDate = String[8];
  TClient = record
    Name: TNameStr;
    {...}
  end;
  TPurchess = record
    Date: TDate;
    Value: Real;
    Client: Integer;
  end;
var
  fc: file of TClient;
  fp: file of TPurchess;
  Clients: array [1..10] of TClient;
  ClientCnt: Integer;
  p: TPurchess;
begin
  Assign(fc,'file1.bin'); Reset(fc);
  while not EoF(fc) and (ClientCnt<High(Clients)) do begin
    Inc(ClientCnt); Read(fc,Clients[ClientCnt]);
  end;
  Close(fc); {$I-}
  Assign(fp,'file2.bin'); Reset(fp);
  if IOResult<>0 then Rewrite(fp);
  Seek(fp,FileSize(fp));
  with p do
    repeat
      Write('Дата: '); ReadLn(Date);
      if Date='' then Break;
      Write('Сумма: '); ReadLn(Value);
      repeat
        Write('Номер клиента: '); ReadLn(Client);
        if (Client>=Low(Clients)) and (Client<=ClientCnt) then begin
          WriteLn('Клиент: ',Clients[Client].Name);
          Break;
        end else WriteLn('*** Ошибочный номер клиента');
      until False;
      if not (Date='') then Write(fp,p);
    until Date='';
  Close(fp);
end.