动态选择，表单显示在网页上的多个位置

Question

我有一个表单部分显示在网页，标题和页脚的多个位置。但是我想进行动态选择，它需要一个id才能正常工作。如果我将id添加到partial，它将出现在多个位置。我该如何处理jquery？

JQUERY：

jQuery ->
  category = $('#subject_category').html()
  $('#subject_product').change ->
    product = $('#subject_product :selected').text()
    escaped_product = product.replace(/([ #;&,.+*~\':"!^$[\]()=>|\/@])/g, '\\$1')
    options = $(category).filter("optgroup[label='#{escaped_product}']").html()
    if options
      $('#subject_category').html(options)
      $('#subject_category').parent().show()
    else
      $('#subject_category').empty()
      $('#subject_category').parent().hide()

_FORM_PARTIAL：

  <%= form_for( subject ,:html => { :class => "form-inline img-rounded subject"}) do |f| %> 
          <div class="form-group">
            <%= f.select( :product, Subject.products,{:placeholder => "Car"},{class: "form-control input-lg product_select"}) %>

            <%= %>

            <%= f.select( :category, grouped_options_for_select(Subject.grouped_options) ,{:placeholder => "Handles"},{class: "form-control input-lg category_select"}) %>
            <%= f.submit "Submit", {class: 'btn btn-danger btn-lg'} %>
          </div>
      <% end %>