[squid-users] multiple acls not working

hi
   I have following configuration

#USER_ACL
  acl user_manish proxy_auth manish
  acl user_indus proxy_auth indus

# USER_RULE_ACL
  acl rule_1 port 901
  acl rule_2 dstdomain manish.tux

# HTTP_ACCESS
  http_access deny user_manish rule_2
  http_access allow user_manish rule_1

   I belive that above configuration shall block manish.tux for user manish and open port 901 access for user manish.
    but it is not behaving in this way. it blocks access to all sites.
    if i m wrong in configuration can some one pls tell me what shall i do to achive above motive.

Regards

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Manish Kumar Arya