title: AngularJS textbox value returns undefined
body: <p>When I press my button, I want to print the value of my textbox in my console. But my textbox returns a undefined. It seems that all of the code are working perfect, I did it the same way as some other code I used before, but it isn't working now.</p>
  
  <p>This is my html code:</p>
  
  <pre><code>&lt;form class="form-horizontal"&gt;    
       &lt;input type="text" ng-model="add" ng-model-instant&gt;&lt;button class="btn" ng-click="order()"&gt;&lt;i class="icon-plus"&gt;&lt;/i&gt;Order!&lt;/button&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>This is my script:</p>
  
  <pre><code>angular.module('MyApp', []).
  config(function($routeProvider) {
      $routeProvider.  
          when('/boeken', {templateUrl:'partials/boeken.html', controller:BoekenCtrl}).
          when('/orders', {templateUrl:'partials/orders.html', controller:OrderCtrl}).
          when('/home', {templateUrl:'partials/home.html', controller:HomeCtrl}).
          otherwise({redirectTo:'/home'});
  });
  
  //BoekenCtrl
  
  //HomeCtrl
  
  function OrderCtrl($rootScope) {    
      $rootScope.order = function() { console.log($rootScope.add); $rootScope.add = "";     };
  }
  </code></pre>
  
  <p>Why is it that my textbox is undefined?</p>