has_many :through association

To make it a bit more clear: in my form (for edit and new) I have the following:

<% for menu in Menu.find(:all) %>   <tr>     <td><%= check_box_tag "group[menu_ids]", menu.id, @group.menus.include?(menu) %></td>      <td><%= menu.title %></td>   </tr> <% end %>

But this is not for what i would like ! (if it is even possible :stuck_out_tongue: )