# To guard against CSRF, the user's session id (sid)
# can be stored on a form. This function will check
# (for logged in users) that the sid on the form matches
# the session id in the cookie.
# To guard against CSRF, the user's session id (sid)
# can be stored on a form. This function will check
# (for logged in users) that the sid on the form matches
# the session id in the cookie.