Hi, Could anyone help me pass a user_id when creating a child record with a HABTM relationship? I''m basically trying to create a record from the following url /users/:id/tasks/new I tried several variants of the following, but keep getting various errors. My first attempt below yeilds ''invalid Users'' error and the second yields a type mismatch error "user expected got string." <% form_for(@tasks) do |f| %> #things I tried: <%= hidden_field_tag "tasks[user_ids][]", params[:user_id] %> <%= f.hidden_field :user_ids, params[:user_id] %> <%= f.submit ''Create'' %> <% end %> I get why I''m getting these errors, but haven''t been able to figure out the correct syntax to get it to pass through. perhaps I''ve been making the wrong assumption that if I could pass the user_id to my create_action, rails would understand that it needed to create the HABTM between the new record and the user_id I''m referencing. Any help would be appreciated. Thanks! -MG -- Posted via http://www.ruby-forum.com/.