Dropdown menu does not work

I am using Ruby 1.9.3 and Rails 3.2.16.

My bootstrape dropdown menu not working. I have no idea why?

Gemfile contain:

ruby "1.9.3"
gem 'rails', '3.2.16'
gem 'bootstrap-sass', '2.1'
gem "watu_table_builder", :require => "table_builder", :git =>
"git://github.com/watu/table_builder.git"
gem 'bcrypt-ruby', '3.0.1'

group :development, :test do
  gem 'sqlite3', '1.3.5'
end

group :assets do
   gem 'sass-rails', '3.2.5'
   gem 'coffee-rails', '3.2.2'
   gem 'uglifier', '1.2.3'
   gem 'jquery-ui-rails'
end

gem 'jquery-rails'
gem 'jquery_datepicker', '~> 0.4'

group :production do
  gem 'pg', '0.12.2'
end

Code of application.js:

//= require jquery-ui
//= require jquery_ujs
//= require bootstrap-dropdown
//= require bootstrap
//= require jquery
//= require_tree .

I have taken reference of
[this]http://stackoverflow.com/questions/10218587/twitter-bootstrap-drop-down-suddenly-not-working
link. But this problem does not solve.

Could you help me on this?

Kind regards.

Does the javascript console ( F12 ) show any errors ?

Sampath Weerasinghe wrote in post #1153678:

Does the javascript console ( F12 ) show any errors ?

When I used code in application.js as per javascript load order like as

follow:

//= require jquery
//= require jquery_ujs
//= require jquery-ui
//= require bootstrap
//= require_tree .

I got error in javascript console like:

" Uncaught Error: jquery-ujs has already been loaded! ".

I have solved this issue.

I add following code in users.js.coffee:

jQuery ->
$('.dropdown-toggle').dropdown()