function set_class_col($col, $val = '')
 {
     if (!isset($col) || empty($col)) {
         return false;
     }
     $validator = new validator();
     $isValid = $validator->check_value($col, $val, $col, "string", 0, 255);
     if ($isValid) {
         $this->{$col} = $val;
     } else {
         foreach ($validator->error_list as $key => $data) {
             $this->set_message($validator->error_list[$key]["msg"]);
         }
     }
     return $isValid;
 }