public function assetsBackend()
 {
     static $once;
     if ($once != null) {
         return;
     }
     $once = true;
     $path = $this->getAssetsPath();
     N2CSS::addInline('.n2-expert {display: none !important;');
     N2CSS::addFile($path . "/admin/css/smartslider.css", 'smartslider-backend');
     foreach (glob($path . "/admin/js/*.js") as $file) {
         N2JS::addFile($file, 'smartslider-backend');
     }
     if (!N2Base::getApplication('smartslider')->storage->get('free', 'rated')) {
         N2JS::addFile($path . "/admin/js/free/gopro.js", 'smartslider-free');
     }
     foreach (glob($path . "/admin/js/element/*.js") as $file) {
         N2JS::addFile($file, 'smartslider-backend');
     }
     N2Localization::addJS(array('Insert', 'Insert variable', 'Choose the group', 'Choose the variable', 'Result', 'Filter', 'No', 'Clean HTML', 'Remove HTML', 'Split', 'Chars', 'Words', 'Start', 'Length', 'Find image', 'Index', 'Find link', 'Index'));
     foreach (glob($path . "/admin/js/generator/*.js") as $file) {
         N2JS::addFile($file, 'smartslider-backend');
     }
     foreach (glob($path . "/admin/js/item/*.js") as $file) {
         N2JS::addFile($file, 'smartslider-backend');
     }
     foreach (glob($path . "/admin/js/item/parser/*.js") as $file) {
         N2JS::addFile($file, 'smartslider-backend');
     }
     foreach (glob($path . "/admin/js/layer/*.js") as $file) {
         N2JS::addFile($file, 'smartslider-backend');
     }
     N2Form::$documentation = 'http://doc.smartslider3.com/';
 }