def append_js!(html, after_script_name, script_name)
      html.sub!(script_matcher(after_script_name)) do
        "#{$~}\n" + helper.javascript_include_tag(script_name)
      end
    end
def append_js!(html, after_script_name, script_name)
      html.sub!(script_matcher(after_script_name)) do
        "#{$~}\n" + helper.javascript_include_tag(script_name)
      end
    end
Appends the given `script_name` after the `after_script_name`.