For the following code sample, the params does not seem to take affect. but if I put the param as part of url then it works fine. Both are supposed to be equivalent. However putting in params generates uncaught object exception. Where am I going wrong.
 $stateProvider.state('start', {
        params: ['lang'],
        views : {
            'navbar' : {
                templateUrl: function($stateParams) {
                    return '/static/html/' + $stateParams.lang +  '/navbar.html';
                }
            },
            'jumbotron' : {
                templateUrl: function($stateParams) {
                    return '/static/html/' + $stateParams.lang + '/jumbotron.html';
                }
            },
            'main_content' : {
                templateUrl: function ($stateParams) {
                    return '/static/html/' + $stateParams.lang + '/main_content.html';
                }
            }
        },
        url: '/'
    })
 
     
    