Movie vs. Book

We are about to go see Percy Jackson and the Olympians. I like the book, but I never trust the movie to be like the book. My friends say that the movie is nothing like the book. Apparently the movie is good if you haven't read the book, so I'm very suspicious. I like the books, but I'm stuck on the third book, The Titan's Curse(The blue book). So I'll make another post once I see the movie.