return json_encode($json); } } $Engine = new Engine(); switch ($_GET['mod']) { case 'add_lib': echo $Engine->addLib(); break; case 'saveLib': echo $Engine->saveLib(); break; case 'editLib': echo $Engine->editLib(); break; case 'library': echo $Engine->library(); break; case 'deleteLib': echo $Engine->deleteLib(); break; case 'addBook': echo $Engine->addBook(); break; case 'editBook': echo $Engine->editBook(); break; case 'saveBook': echo $Engine->saveBook(); break; case 'bookList': echo $Engine->bookList();