ng-Repeat Filter on Boolean

<!DOCTYPE html>
<html>

<head>
    <title></title>
    <meta charset="utf-8" />
    <script src="Scripts/angular.js"></script>
    <script>
        angular.module('myApp', []).controller("myAppCtrl", function($scope)
            {
            $scope.isRegistered = 'false';
            $scope.users = [
              {
                name: 'user1 (registered)',
                registered: true
            }, {
                name: 'user2 (unregistered)',
                registered: false
            }, {
                name: 'user3 (registered)',
                registered: true
            }, {
                name: 'user4 (unregistered)',
                registered: false
            }];
        });
    </script>
</head>

<body ng-app="myApp">
    <div ng-controller="myAppCtrl">
        <h3>Unregistered Users</h3>
        <div ng-repeat="user in users | filter:{registered:false}">
            <div class="row-fluid">
                <div class="span2">
                    {{user.name}}
                </div>
            </div>
        </div>
        <h3>Registered Users</h3>
        <div ng-repeat="user in users | filter:{registered:true}">
            <div class="row-fluid">
                <div class="span2">
                    {{user.name}}
                </div>
            </div>
        </div>
    </div>
</body>

</html>