function unavailable()
 {
     $plugin_data = $this->_getPluginFromRequest();
     if ($plugin_data) {
         $plugin_manager = $this->plugin_manager;
         $dependencies = $this->dependency_solver->getAvailableDependencies($plugin_data['plugin']);
         if ($dependencies) {
             $error_msg = $GLOBALS['Language']->getText('plugin_pluginsadministration', 'error_avail_dependency', array($plugin_data['plugin']->getName(), implode(', ', $dependencies)));
             $GLOBALS['Response']->addFeedback('error', $error_msg);
             return;
         }
         if ($plugin_manager->isPluginAvailable($plugin_data['plugin'])) {
             $plugin_manager->unavailablePlugin($plugin_data['plugin']);
             $GLOBALS['Response']->addFeedback('info', $GLOBALS['Language']->getText('plugin_pluginsadministration', 'feedback_unavailable', array($plugin_data['name'])));
         }
     }
 }