Many to many relationship , rails -

i have many-to-many relation between users , channels subscribe to. when @ model dependency between user , user channels or channels , users channel instead there direct connection between users , channels. how put users channels between two? user model

class user < activerecord::base    acts_as_authentic    roles = %w[admin  moderator subscriber]    has_and_belongs_to_many :channels   has_many :channel_mods   named_scope :with_role, lambda { |role| {:conditions => "roles_mask & #{2**roles.index(role.to_s)} > 0 "} }   def roles       roles.reject { |r| ((roles_mask || 0) & 2**roles.index(r)).zero? }     end    def roles=(roles)       self.roles_mask = (roles & roles).map { |r| 2**roles.index(r) }.sum     end    def role_symbols     role.map |role|       role.name.underscore.to_sym     end   end      end 

channel model

class channel < activerecord::base   acts_as_taggable   acts_as_taggable_on :tags   has_many :messages   has_many :channel_mods   has_and_belongs_to_many :users  end 

userschannel model

class userschannels < activerecord::base end 

see has_many :through documentation on rails guides guides through configuring has_many relationship intervening model.