'Mark a session item'

def do_mark(self, input):

    (argc, argv) = util.parseinput(input, 2)
    if (argc == 0):
        return self.do_session(input)
    elif (argc == 1):
        return self.help_mark()
    elif (argc == 2):
        try:
            index = int(argv[0])
            value = argv[1]
        except (IndexError, ValueError):
            raise exception.CmdErr, 'Invalid    index'
        item = self.session.get_item(index)
        item.set_status(value)
        self.io.print_success(('Item    marked    as    %s' % value))
