In order to post you have to be signed in. If this has not happened automatically you may need to do it manually.
Either at the top right of the page or near the top-middle should be a link/button labelled "sign in" or "sign in to post." Go ahead and click on that.
If you want to use your gmail account, if you have one, that will work. If you want to use another e-mail address, such as your UF Department of Medicine e-mail, you will probably need to click on the "Create an Account" button.
Under "your current e-mail address" go ahead and use the e-mail address you wish to use for signing in, such as your UF Medicine e-mail account.
The password does NOT need to be your UF Medicine e-mail password. It can be anything you want it to be.
Fill out the bottom half of the page and click on the button labeled "I accept. Create my account."
Your should be "good to go." Call or e-mail me if this doesn't work of you have problems.
David