I want to make a table within a form by making a new form_tag. The following code in ApplicationHelper fails:

module ApplicationHelper

class TabularFormBuilder < ActionView::Helpers::FormBuilder 
   # ... code to insert <tr> tags </tr> 
end

def tabular_form_for(name, object = nil, options = nil, &proc) 
   concat("<table>", proc.binding) 
   form_for(name, 
   object, 
   (options||{}).merge(:builder => TabularFormBuilder), 
   &proc) 
   concat("</table>", proc.binding) 
  end
end

The view I use is:

<h1>New project</h1>
<% tabular_form_for :project, :builder => ApplicationHelper::TabularFormBuilder do |f| %>
  <%= f.error_messages %>
  <%= f.text_field :name %>
  <%= f.text_area :description %>
  <%= f.text_field :location %>
  <%= f.submit 'Create' %>
<% end %>

The error I get is:

NoMethodError in Projects#new Showing app/views/projects/new.html.erb where line #5 raised: undefined method `errors' for {:builder=>ApplicationHelper::TabularFormBuilder}:Hash

Any ideas how to make this custom tag work?