Angular: get module by name

How to get module by name?

HTML

<script src="http://code.angularjs.org/angular-1.0.0rc9.js"></script>
<html ng-app='MyApp'>
    <body>
        <div ng-controller="Ctrl1">
            {{name}}
        </div>
        <div ng-controller="Ctrl2">
            {{name}}
        </div>
    </body>
</html>

JavaScript

var app = angular.module('MyApp',[]);
app.controller('Ctrl1', ['$scope',function($scope) {
    $scope.name = '111';
}]);

// I want to add something to the module `MyApp` in another file
// but following line doesn't work
app = angular.module('MyApp',[]);
app.controller('Ctrl2', ['$scope',function($scope) {
    $scope.name = '222';
}]);
document.write('        <div ng-controller="Ctrl1">\
{{name}}\
        </div>\
        <div ng-controller="Ctrl2">\
            {{name}}\
        </div>')