Original doc:
    Display a buttonbox with the specified choices.
    Return the index of the choice selected.

def indexbox(message="Shall I continue?", title="", choices=["Yes", "No"]):
    """
    Original doc:
    Display a buttonbox with the specified choices.
    Return the index of the choice selected.
    """
    reply = buttonbox(message, title, choices)
    index = -1
    for choice in choices:
        index = index + 1
        if reply == choice:
            return index