看看这句为什么错了,该怎么处理

看看这句为什么错了
第9行MOVE那句错了
procedure TForm1.auHTTP1HTTPError(Sender: TObject; ErrorCode: Integer;
  Stream: TStream);
var
  Str: String;

begin

  SetLength(Str, Stream.size);
  Move(Stream.Memory^, Str[1], Stream.size);
  case ErrorCode of

  404: Str := '404: 文件不存在';

  403: Str := '错误：403目录存在';

  else // Mysterious reason

  Str := IntToStr(ErrorCode);

  end;
  showmessage(Str);

end;

[Error] Unit1.pas(140): Undeclared identifier: 'Memory'

[解决办法]
TMemoryStream(Stream).Memory
[解决办法]
Move(Stream.Memory^, Str[1], Stream.size); => Stream.ReadBuffer(Str[1], Stream.Size);

Delphi(Pascal) code

procedure TForm1.auHTTP1HTTPError(Sender: TObject; ErrorCode: Integer; Stream: TStream);var  S: String;begin  SetLength(S, Stream.Size);  Stream.Seek(0, soFromBeginning);  Stream.ReadBuffer(S[1], Stream.Size);  case ErrorCode of    404:      S := '404: 文件不存在';    403:      S := '错误：403目录存在';    else      S := IntToStr(ErrorCode);  end;  ShowMessage(S);end;