delphi idHttp下载文件

procedure TForm1.Button3Click(Sender: TObject);
var
h:TIdhttp;
res : String;
MyStream:TMemoryStream;
begin
MyStream:=TMemoryStream.Create;
h:=Tidhttp.Create(nil);
try
h.get('http://www.oro.com/project2.exe',MyStream);
except
showmessage('网络出错!');
MyStream.Free;
exit;
end;
MyStream.SaveToFile('c:/1.exe');
MyStream.Free;
end;