Missing controller

You are seeing this error because controller DiscussController could not be found.

Notice: this error is being rendered by the app/views/errors/missing_controller.thtml view file, a user-customizable error page for handling invalid controller dispatches.

Fatal: Unable to load controller DiscussController

Fatal: Create Class:

class DiscussController extends AppController
    var $name = 'Discuss';

in file : app/controllers/discuss_controller.php