OperationalError: near "?": syntax error sqlite3 error

I am trying to add two values in a table by calling functions of a file. The file has following code:

import sqlite3
con = sqlite3.Connection('rdb')
cur = con.cursor()
def insert(s):
    cur.execute("create table if not exists customerorder(no number primary 
    key,menuitems varchar(40))")
    c=1
    for i in s:
        print c
        print i
        cur.execute("insert into customerorder(?,?)",(int(c),i))
        c += 1 

def fetch():
    cur.execute("select * from customerorder")
    print cur.fetchall()

Here 's' is a list. Having s[0]='simple book' and s[1] = 'advance book'.