I can't get why, but suddenly my Bootstrap Carousel stopped working. I want it starts onload.

Error from Chrome Console:

          Uncaught TypeError: Object [object Object] has no method 'carousel' :3000/assets/application.js?body=1:18
          (anonymous function) :3000/assets/application.js?body=1:18
         jQuery.Callbacks.fire jquery-1.7.2.js:1076
        jQuery.Callbacks.self.fireWith jquery-1.7.2.js:1194
        jQuery.extend.ready jquery-1.7.2.js:436
        DOMContentLoaded jquery-1.7.2.js:950

In my application.js:

        $('.carousel').carousel({
        interval: 2000
       })

In my layout:

       <%= javascript_include_tag 'jquery-1.7.2', 'jquery.validate.min','application' %>

Where is problem ?