procedure CopyFile(Source, Dest: string);
var
  SrcFile: Integer;
  DestFile: Integer;
  S: string;
  RetCode: Longint;
  OpenFileBuf: TOFStruct;
  FName: array[0..255] of Char;
begin
  StrPCopy(FName, Source);
  SrcFile := LZOpenFile(FName, OpenFileBuf, of_Read);
  StrPCopy(FName, Dest);
  DestFile := LZOpenFile(FName, OpenFileBuf, of_Create);

  RetCode := LZCopy(SrcFile, DestFile);
  if RetCode >= 0 then
  begin
    LZClose(SrcFile);
    LZClose(DestFile);
  end
  else
  begin
    Str(RetCode, S);
    MessageDlg('Не могу скопировать ' + Source + ' в ' +
      Dest + #13 + 'Код ошибки = ' + S, mtError, [mbOk], 0);
  end;
end;