Was Madison pettis in horton hears a who?

Yes, Madison Pettis voiced the character of "JoJo" in the animated film "Horton Hears a Who!" released in 2008. The movie is based on Dr. Seuss's children's book and features Horton the elephant, who discovers a tiny world on a speck of dust. Pettis's character, JoJo, is the son of the Mayor of Whoville and plays a significant role in the story.