<%= form_tag course_attach_relations_path, method: :post, remote: true, id: "relation_file_form" do %> <%= hidden_field_tag(:file_id, file.id) %> <%= content_tag('div', courses_check_box_tags('courses[course][]', User.current.courses,course,file), :id => 'courses')%> 引  用取  消 <% end -%>