It looks like nobody noticed that you wrote "commend", probably instead of "comment". If you meant comment (which really makes sense) then yes it is okay to comment. And you already got your answers. But if you meant what you wrote then please clarify.
Yes, commend is what i really meant and not comment. I mean to say something like; "OP, you nailed it, this is what I have been looking for, thanks for taking your time to post this good job.
I have also gotten my answer, it is not needed if it doesn't add value to the post or I should merit such post when I have merit to give.