Missing Method in SitesController

Error: The action robots.txt is not defined in controller SitesController

Error: Create SitesController::robots.txt() in file: app/controllers/sites_controller.php.

<?php
class SitesController extends AppController {

	var $name = 'Sites';


	function robots.txt() {

	}

}
?>

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