title: Angular JS - go to otherwise state without changing the URL
body: <p>Hi I have been using <code>stateprovider</code> for a long time and this time I want to implement a functionality in which without changing the url, I want to go <code>not found state</code> but not on url.</p>
  
  <p>This is my code.</p>
  
  <pre><code>(function () {
  angular.module('mean').config(aosOfferConfig);
  
  function aosOfferConfig($stateProvider, $urlRouterProvider) {
      $urlRouterProvider.otherwise("/link/404_not_found");
      $stateProvider
          .state('offers', {
              url: '/offers/packages',
              templateUrl: 'views/aosOffers/aosoffers.html',
              controller: 'offersController',
              controllerAs: 'packages'
          })
          .state('offersignup', {
              url: '/offers/signup',
              templateUrl: 'views/aosOffers/offerssignup.html',
              controller: 'offersSignupController',
              controllerAs: 'offerssignup'
          })
          .state('thankyou', {
              url: '/offers/thankyou',
              templateUrl: 'views/aosOffers/offersthankyou.html'
          });
      }
  })();
  </code></pre>
  
  <p>Now in my otherwise part I am taking the user to <code>/link/404_not_found</code>. I don't want this. Instead, I want that it will remain in current url but the state should be changed. Just like github does.</p>
  
  <p>How can I do this ? </p>