some of the Angular examples don't work with current version of angular.js
the example at http://www.w3schools.com/angular/tryit.asp?filename=try_ng_controller
works fine until you change the version from 1.2.26 to 1.3.11
so change the line
<script src= "http://ajax.googleapis.com/ajax/libs/angularjs/1.2.26/angular.min.js"></script>
to
<script src= "http://ajax.googleapis.com/ajax/libs/angularjs/1.3.11/angular.min.js"></script>
This also applies to other examples that use controllers.