Trader tab is gone

I built the branch office, and some one told me that there is a trade tab on the messaging. I checked and it was there. This a a couple of days ago. I know that since Friday I've had no tab so I can't trade. This is unfortunate since trading seems kind of necessary to help move the growth along.

Delete your cookies, clear your cache, delete your temporary internet files. If the trade tab still does not reappear, try a different browser, most people recommend Firefox.

Thanks for the response. I'll give Firefox a try.