def format_string( oldString ):
    """
    This function turns a given string (one of the two arguments passed to the
    script by the user) into one that can be used as part of the URL used to
    fetch the page from the lyrics wiki.  Specifically, it needs to be camel-
    case (or 'title' case) with underscores replacing spaces.
    """
    string = oldString.title()
    return( string.replace( ' ', '_', -1 ) )