Dear zopist

I have a trying time using Cookie Crumbler 1.2 with Zope2.8.4 (windows version).
I could NOT figure out how to log out a user.  I have simplified to the orginal logged_out form to this:

<dtml-call "RESPONSE.expireCookie('__ac_name')">
    <a href="/manage_zmi_logout">logout</a>

However, neither this nor the original logged_out dtml seems to work.
Is it because I am using frames in my dtml that causes it or I am getting the concept of how Cookie Crumbler works?

Thank you.