Form_for helper?

How would make this a helper? I would like to send in some parameters
as a hidden field dynamically.

<% form_for :file, :url => file_upload_path(:format => ‘js’), :html =>
{ :multipart => true, :target => ‘upload_file’, :id => ‘fileupload’ }
do %>
File: 
<%= file_field_tag :upload %> 
<%= hidden_field_tag ‘w_id’, @work.id %>
<%= submit_tag ‘Upload File’ %> 
<% end %>