Angular: Empty Fiddle

http://angularjs.org/

HTML

<script src="http://code.angularjs.org/angular-1.0.1.js"></script>
<div ng-controller="MyCtrl">
   {{message}}!
    <button ng-click="changeMessage()">change Message</button>
</div>

JavaScript

var myApp = angular.module('myApp',[]);

function MyCtrl($scope, $http) {
    $scope.message = 'Hello $scope';
	$scope.newMessage = 'Hello World';
    $scope.changeMessage = function(){
        // if you comment $scope.message, and uncomment 'debugger', then run the 				// fiddle(with opened console),
        // and click the button, and after than write $scope in the console, you'll get 		// this message:
        // Uncaught ReferenceError: $scope is not defined
        // but if you uncomment $scope.message, it will work just fine
        // and in that case, $scope.newMessage will be accessible
        $scope.message = $scope.newMessage;
        //debugger;
    }
}