Cannot close Twitter Bootstrap Alert using data dismiss button in Rails -

i have following div in devise => sessions

<div class="widgettitle">     <button type="button" class="close" data-dismiss="alert">×</button>     <%= "<div class=\"flash_error\">#{h alert}</div>".html_safe unless alert.blank? %>     <%= "<div class=\"flash_notice\">#{h notice}</div>".html_safe unless notice.blank? %>   </div> 

but close button not working.. can please ...?

hi have appropriate js included?

assuming trying use twitter bootstrap's alert functionality?

!function ($) {    "use strict"; // jshint ;_;    /* alert class definition   * ====================== */    var dismiss = '[data-dismiss="alert"]'     , alert = function (el) {         $(el).on('click', dismiss, this.close)       }    alert.prototype.close = function (e) {     var $this = $(this)       , selector = $this.attr('data-target')       , $parent      if (!selector) {       selector = $this.attr('href')       selector = selector && selector.replace(/.*(?=#[^\s]*$)/, '') //strip ie7     }      $parent = $(selector)      e && e.preventdefault()      $parent.length || ($parent = $this.hasclass('alert') ? $this : $this.parent())      $parent.trigger(e = $.event('close'))      if (e.isdefaultprevented()) return      $parent.removeclass('in')      function removeelement() {       $parent         .trigger('closed')         .remove()     }      $.support.transition && $parent.hasclass('fade') ?       $parent.on($.support.transition.end, removeelement) :       removeelement()   }    /* alert plugin definition   * ======================= */    var old = $.fn.alert    $.fn.alert = function (option) {     return this.each(function () {       var $this = $(this)         , data = $this.data('alert')       if (!data) $this.data('alert', (data = new alert(this)))       if (typeof option == 'string') data[option].call($this)     })   }    $.fn.alert.constructor = alert    /* alert no conflict   * ================= */    $.fn.alert.noconflict = function () {     $.fn.alert = old     return   }    /* alert data-api   * ============== */    $(document).on('click.alert.data-api', dismiss, alert.prototype.close)  }(window.jquery); 

how using twitter bootstrap in application?

have included //= require bootstrap in application.js file? required preference of using gem bootstrap-sass (relies on gem sass-rails)