If you are trying to reply to a thread in Caption This and cannot, please report that. If you are trying to begin a new thread in Caption This, you will not be able to. That forum is sponsored by TCS. The new threads are started by the forum moderator (me).
If you have a picture to submit, see the instructions in the forum for doing so.
You have to be 18 to post in IMO. Sweetie, if you would take the time to read the forum rules and some specific guidelines in some of the specific forums, like Caption This and IMO, all of your questions would be answered. We really aren't keeping things a secret around here.