Missing Method in DocumentsController

Error: The action M is not defined in controller DocumentsController

Error: Create DocumentsController::M() in file: app/controllers/documents_controller.php.

<?php
class DocumentsController extends AppController {

	var $name = 'Documents';


	function M() {

	}

}
?>

Notice: If you want to customize this error message, create app/views/errors/missing_action.ctp