Translation of なんだから


I don't really get the meaning of それまでなんだから in below sentence:

> たとえ試験が全部できても名前書き忘れたら「それまでなんだから」、くれぐれも忘れないように。

Does it mean that there is no point in doing well in an exam if you forget to
write your name down?




「それまで」 is a call when a game or an exam end. So, it means "because it'd be
over then" in the sense that you virtually immediately fail the exam.




「それまで」 is a call when a game or an exam end. So, it means "because it'd be
over then" in the sense that you virtually immediately fail the exam.

