What's that movie called, where some kids run away from their parents on christmas or something and they are in a airport and causing trouble?

This maybe? Unaccompanied Minors (2006) - IMDb (http://www.imdb.com/title/tt0488658/) (AKA Grounded)

Thank you, Frogdude! That is the movie I was thinking of! :D

You're very welcome!