Summernote not working

am new to rails, am using summernote for my app, I have followed the
whole
documentation and did as per the documentation. but, the editor is not
dispalying in my text_area. means it just shows a blank text area box
with
out any buttons, the details are below.

In my gem file:

gem ‘simple_form’, ‘2.1.1’
gem ‘summernote-rails’, ‘0.4.0’
gem ‘bootstrap-sass’, ‘3.1.1.1’
gem ‘bootstrap-will_paginate’, ‘0.0.10’
gem ‘font-awesome-sass-rails’, ‘3.0.2.2’

In app/assets/javascripts/application.js

//= require jquery
//= require jquery_ujs
//= require bootstrap
//= require summernote.min
//= require_tree .

in app/assets/stylesheets/application.css

*= require_self
*= require_bootstrap
*= require_font-awesome
*= require_summernote
*= require_tree .

In my events/_form.html.erb

<%= f.input :error_detail, label:‘Summary’, class:‘summernote’,
input_html:
{class:‘form-control’} %>

in my app/assets/javascripts/events.js.coffee

$ ->

to set summernote object

You should change ‘#event_error_detail’ to your textarea input id

summer_note = $(’#event_error_detail’)

to call summernote editor

summer_note.summernote

to set options

height:300
lang: ‘en’

toolbar: [

        # ['insert', ['picture', 'link']], // no insert buttons
        # ["table", ["table"]],
        # ["style", ["style"]],
        # ["fontsize", ["fontsize"]],
        # ["color", ["color"]],
        # ["style", ["bold", "italic", "underline", "clear"]],
        # ["para", ["ul", "ol", "paragraph"]],
        # ["height", ["height"]],
        # ["help", ["help"]]
     #]

to set code for summernote

summer_note.code summer_note.val()

to get code for summernote

summer_note.closest(‘form’).submit ->

alert $(’#event_error_detail’).code()

summer_note.val summer_note.code()
true

The error am getting in my firefox browser’s error console

TypeError: summer_note.summernote is not a function

MY ENVIRONMENT DETAILS: Ruby 1.9.3 and Rails 3.2.8, ubuntu 12.4

Please help me where am i doing wrong…, Please I need help.