When you click on reply, there is a box at the bottom that you type your post in. At the top of that box is "Go to", and then Message List, Search, Control Center, and Log Out. Click on Control Center there.
Poor me had to REGISTER to get access to Control Center. Went to message reading display options and selected "multiple messages per page threaded". Now I can be lazy and read all posts at once! Oh, shoot, I think I just wrote a post. meow.