Which Animated Movie Is This?

Okay, my friend and I have been trying to figure this out for the last hour. There is a Disney-like animated movie(but I'm not sure if it is Disney) and it's about this little girl who gets kidnapped by trolls. All we can remember is that a little boy is looking for her. Oh, and at some point in the movie, he is skipping through the forest with a lantern, singing. Please, if you have any idea let me know. Thanks~