Formtastic :destroy action as a button - ruby-on-rails

Question

I want to add delete button in actions. but all it does is js goback. I tried <%= f.actions %> didn't show the delete button. below is my effort to add it manually.
<% if can? :update, #parking_branch %>
<%= semantic_form_for #parking_branch do |f| %>
<%= f.semantic_errors %>
<%= f.inputs do %>
<%= f.input :parking_company_id, :as => :select, :collection => Hash[ParkingCompany.all.map {|c| [c.company_name,c.id]}], :required => true %>
<%= f.input :branch_name, :required => true %>
<%= f.input :email, :required => true %>
<%= f.input :telephone, :required => false %>
<%= f.input :latitude, :hint =>"Automatically filled based on address" %>
<%= f.input :longitude, :hint =>"Automatically filled based on address" %>
<%= f.input :airport, :required => true %>
<%= f.input :address1 %>
<%= f.input :address2, :required => false %>
<%= f.input :address3, :required => false %>
<%= f.input :city %>
<%= f.input :county %>
<%= f.input :postcode %>
<%= f.input :country, :as => :country, :priority_countries => ["United Kingdom"], :required => true %>
<% end %>
<br />
<%= f.actions do %>
<%= f.action :submit, :button_html => {:class => 'btn-primary', :disable_with => 'Please Wait...' } %>
<%= f.action :cancel, :button_html => {:class => 'btn-danger', :disable_with => 'Please Wait...', :method => :delete } %>
<% end %>
<% end %>
<% else %>
<br />
<h1> You are not authorised to do this! <h1>
<% end %>
I have destroy action in my controller too