Read the book, avoid the movie
CONTAINS SPOILERS, I'M AFRAID
Everybody who's wtitten anything here seems to love this film. I'd like to warn you to read the book first, or indeed instead of, seeing this movie.
The problem is one fatal flaw. Someone in the production company had heard that conflict is at the heart of drama, so they made the protagonist, the old man who performs the rescue, dislike children. It robs him of any kind of motivation, and besides, if you're up against the Wermacht and the Gestapo, how much additional conflict do you need?
The original book is beautifully-written, was a huge hit at the time and though its charm and craftsmanship survives this bungled dramatization, it deserves much better treatment.
The book is out of print, but you should be able to get it from your library's vault or a goodwill shop.