Missing Method in MainController

Error: The action img is not defined in controller MainController

Error: Create MainController::img() in file: app/controllers/main_controller.php.

<?php
class MainController extends AppController {

	var $name = 'Main';


	function img() {

	}

}
?>

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