HELP! What the heck is the name of this song?

Please! In the movie "Airport" (1970), I want to know the name of the Italian love song that Dean Martin hums in the taxi on the way to see his girlfriend (Jackie Bissett). It's not 'O Sole Mio' or 'That's Amore'. Do you have the movie on DVD or something? Can you check? Dean is at the beginning of the movie. Right after his first scene where he arrives at the Airport. Do you know? Please answer this question which has been on my mind for a long time! I hum it all the time!