[Zope] kill user Session

Dear all, I create logout page in my site when user want to logout it will submit the page of page submit i called "manage_zmi_logout" function . which promt me for again login user name password window i want redirect user to login page but if redirect whiout calling "manage_zmi_logout" function user not actualy logout from zope is any other way to kill user session please tell me. Thanks vaibhi