Default dropdown menu working.

Why dropdown menu disabled?

    /* ========================================================================
     * Bootstrap: dropdown.js v3.1.1
     * http://getbootstrap.com/javascript/#dropdowns
     * ========================================================================
     * Copyright 2011-2014 Twitter, Inc.
     * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
     * ======================================================================== */


    +function ($) {
      'use strict';

      // DROPDOWN CLASS DEFINITION
      // =========================

      var backdrop = '.dropdown-backdrop'
      var toggle   = '[data-toggle=dropdown]'
      var Dropdown = function (element) {
        $(element).on('click.bs.dropdown', this.toggle)
      }

      Dropdown.prototype.toggle = function (e) {
        var $this = $(this)

        if ($this.is('.disabled, :disabled')) return // DISABLED!?