button_to (ActionView::Helpers::UrlHelper)

    # File lib/action_view/helpers/url_helper.rb, line 257
          def button_to(name, options = {}, html_options = {})
            html_options = html_options.stringify_keys
            convert_boolean_attributes!(html_options, %w( disabled ))

            method_tag = ''
            if (method = html_options.delete('method')) && %w{put delete}.include?(method.to_s)
              method_tag = tag('input', :type => 'hidden', :name => '_method', :value => method.to_s)
            end

            form_method = method.to_s == 'get' ? 'get' : 'post'

            request_token_tag = ''
            if form_method == 'post' && protect_against_forgery?
              request_token_tag = tag(:input, :type => "hidden", :name => request_forgery_protection_token.to_s, :value => form_authenticity_token)
            end

            if confirm = html_options.delete("confirm")
              html_options["onclick"] = "return #{confirm_javascript_function(confirm)};"
            end

            url = options.is_a?(String) ? options : self.url_for(options)
            name ||= url

            html_options.merge!("type" => "submit", "value" => name)

            "<form method=\"#{form_method}\" action=\"#{escape_once url}\" class=\"button-to\"><div>" +
              method_tag + tag("input", html_options) + request_token_tag + "</div></form>"
          end