Trying to capture input in If statement [Python]

I have a list.

movie=[the Slow and Confused 9, Somebody, Gorilla vs. King, The Blundering 3: Boss Made Me Do It]

I am trying to toggle between list items using input.

If I key in "N", 1 will be added to i and the respective index will be printed.

My code is:

    i = 0

    while True:
            print("Product", 1 + i, "of", len(movie))
            print("====================")
            print("Name: ", movie[i])
            print("====================")
            print("Enter N for Next Item")
            print("Enter P for Previous Item")
            print("Enter M to return to Main Menu")
            option1input = input("")
            if option1input.upper == "N":
                    i+=1
            elif option1input.upper == "P":
                    i-=1
            elif option1input.upper == "M":
                    break
            else:
                    pass

However, when I key in N, 1 is not added i