要在 form 里动态增加字段，抄袭了 http://railscasts.com/episodes/74-complex-forms-part-2 里面的内容，不知道怎么回事。想请教一下各位：

home.html.erb

1 <%= form_for @add_dev, as: 'add_dev', url: { controller: "home", action: "create" } do |f| %>
2   <%= f.label "Ip" %>
3   <%= f.text_field :ip_addr %>
4   <div id="add_dev">
5     <%= render partial: "sys", collection: @add_dev.syss %>
6   </div>
7   <%= add_dev_link "Add" %>
8   <%= f.submit "Submit" %>
9 <% end %>

_sys.html.erb

1 <%= fields_for "add_dev[syss_attributes][]", sys do |sys_stat| %>
2   <p>
3   Server: <%= sys_stat.text_field :server %>
4   Port: <%= sys_stat.text_field :port %>
5   <%= sys_stat.hidden_field :oid, value: get_oid %>
6   </p>
7 <% end %>

helper

19   def add_dev_link(name)
20     link_to_function name, nil do |page|
21       page.insert_html :bottom, partial: 'sys', object: Sys.new
22     end
23   end

运行没问题，就是点击后没反应！