How to fix an Angular app giving out an empty page in Plunker?

Just defined an app 'Demo' in AngularJS

'use strict';

var app = angular.module('demo', []);
app.controller('DemoCtrl', function($scope) {
    $scope.obj={language_selected : {'name':'Choose a language'}};
    $scope.language_list = [{'name': 'english', 'url': 'https://raw.githubusercontent.com/stevenrskelton/flag-icon/master/png/16/country-4x3/gb.png'},{'name': 'italian', 'url': 'https://raw.githubusercontent.com/stevenrskelton/flag-icon/master/png/16/country-4x3/it.png'}];

});

Now defined an HTML page correspondingly

<!DOCTYPE html>
<html lang="en" ng-app="demo">
<head>
  <meta charset="utf-8">
  <title>AngularJS ui-select</title>


  <script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.2.18/angular.js"></script>
  <script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.2.18/angular-sanitize.js"></script>


  <link rel="stylesheet" href="select.css">

</head>

<body ng-controller="DemoCtrl">

 <div class="select_list" ng-class='{active:active}' ng-click="active=!active">
    <span ng-style="{'background-image':'url('+obj.language_selected.url+')'}">{{obj.language_selected.name}}</span>
    <ul class="options">
        <li class="select_list_option" ng-repeat="language in language_list" ng-click="obj.language_selected=language" ng-style="{'background-image':'url('+language.url+')'}">{{language.name}}</li>
        </ul>
</div>
</body>
</html>

EDIT: Checked the appName -> 'demo' & ng-app is demo & controller is DemoCtrl & ng-controller is DemoCtrl. It is defined appropriately.

The plunker now gives out an empty page.

Am I missing anything here ? Plunker link here: http://next.plnkr.co/edit/nXsUgM7nEsfg7jXh

Solution

You forgot to load you js code, please add

<script src="demo.js"></script>

Here is plunker http://next.plnkr.co/edit/g4yKhngP1TyJ8jLr