Always CTRL+A+C before hitting the POST button. (Make sure you're in HTML mode!!)

On a Mac? CMD+A+C.

COPY YOUR CONTENT TO CLIPBOARD! I can't tell you how many millions of times I lost paragraphs when I was younger due to negligence. Make it a habit! Or, open Notepad, Notes.app and COPY/PASTE what you have so far into your notes so (in case the browser freezes/crashes), you'll be fine.