Hopefully I'm in the right place.

I use Calibre viewer to read books on my computer but somehow the page position box that used to be in the upper left hand corner of my viewer has disappeared. I have no idea what I inadvertently pushed to make this happen, but I'd like it back.
I've tried going back to default and that didn't work. I've searched the forums and googled and nothing. Can anyone tell me in baby terms (relative newbie here) how to get it back where it belongs?
Thanks in advance for any help you can give me.
CJ