Is the Hilary Duff song, "Why Not" another version of "Volare" by Dean Martin?

They song almost identical, except for the fact that one is in italian, and one is in english. But i looked up the lyrics for each, and theyre not the same. So did she just copy this songs tune, or is there more behind it, because this song was featured in her film "The Lizzy McGuire Movie" where she takes a trip to Italy.