<%= bootstrap_form_for(@invitation, layout: :inline) do |f| %> <%= f.select :user_id, options_for_select(@available_users), include_blank: 'Pick a user', skip_label: true %> <%= f.hidden_field :host_id %> <%= button_tag type: :submit, class: 'btn btn-default' do %> Invite New User <% end %> <% end %>