Newsround sits down with Potter stars

Lizo: What's it like being the most famous schoolboy on the face of the planet? Do you get recognised walking around with your friends and how do you cope with it?

Daniel: I do, but it's not been much of a problem because they aren't saying negative things, if they were being nasty it would be a whole different thing but they aren't. They are being perfectly nice and saying positive things about the film too. So, there's no problem really.

Lizo: Now Rupert tell us how much fun did you have with this movie?

Rupert: Yeah, this one was fun! But seeing it finally was the really good bit - 'cos you get to see all the special effects that you didn't get to see when we were making the film.

Lizo: What's it like being the most famous schoolgirl on the planet?

Emma: I don't really feel like that. It feels like I am famous for about two days and then it goes back to being me again.

Lizo: What was it like meeting JK, what was her advice like?

Alfonso: She said I should stay faithful to the spirit of the book not literal. That was entrusting me a lot of freedom. But freedom and responsibility is the same thing - I was like 'oh gosh - am I being faithful to the spirit?'

I give you an example: There's a scene where Malfoy wants to see Buckbeak being executed. It's where Hermione punches him. And there's a sundial. We thought we need something there. I said 'Let's put a graveyard there'.

She says: 'No, you can't have a graveyard there'. And I'm like, 'Why?' She says: 'Oh because the graveyard is near this other wing of the castle and it's going to play an important part in number six because such and such and such.'

Lizo: Did you read through all the books, did JK give you advice?

Gary: I read the third book. I'm now finding out stuff in the 4th and 5th book that I wish I'd known! I just basically read the third book - that's the key that unlocks the part.

CBBC: What do the Weasley twins get up to in this movie?

James: There's the Marauder's Map scene, when Fred and George give Harry the secret map to show him around different passage ways in Hogwarts, which was a good scene.

CBBC: How is this film different to the others?

Matthew: It is scarier and hopefully better than the others. It seemed different to the others when we were filming it. It seemed different because the whole film felt darker and more sinister, which I think will make it better.

CBBC: What do you think the public reaction to Azkaban will be?

Bonnie: It will be big, I think. The spiders scene in the last one got lots of attention, and I think people will be scared by this film too. I think people will like it. People shouldn't worry too much, though. It's scary, but it isn't completely and utterly frightening.