static function model($model)
{
$return = NULL;
$model = HC_App::full_model($model);
if (method_exists($model, 'get_instance')) {
$return = call_user_func(array($model, 'get_instance'));
// $return = $model::get_instance();
} elseif (class_exists($model)) {
$return = new $model();
}
return $return;
}
