What is Mario Lanza's autograph worth?

I have a program from the spring of 1951 "the Knights of Ak-sar-ben present Mario Lanza Tenor star of the films in concert" at aksarben coliseum wednesday, April 25, 1951 8:15pm Omaha Nebraska.. What do you believe it to be worth? The program is folded and a slight bit yellow and a tad bit rough on the edges, but the autograph is nearly perfect..