[Zope] authenticate user

Hi I'm new with Zope and I'm having some difficulties to authenticate a user and his password in the login. I'm trying to use this code: <dtml-with acl_users> <dtml-if "AUTHENTICATED_USER.authenticate('<dtml-var user>','etcUser') and AUTHENTICATED_USER.authenticate('<dtml-var pass>','passwd')> This code is not working, can you help me to do this. Thanks Pedro