我想使用gform_field_validation我找到的这个文档来验证该字段 
,但没有那么有用
    add_filter("gform_field_validation", "custom_validation", 10, 4);
    function custom_validation($result, $value, $form, $field){
       $number = GFCommon::to_number($value,"");
       if (($field["id"] == 1) && ($field["id"] == 1))
           if( ($result["is_valid"]) && ($number >= 1000) && ($number <= 1999)){
               $result["is_valid"] = false;
               $result["message"] = "INCORRECT NUMBER";
           }
       return $result;
    }
任何建议将不胜感激