After you post, if you want to edit, there's a little 'edit' in the box right under your post. Just click on that and it will allow you to edit. As far as quoting only part of a post, I'm not sure how to do that myself. The only way I can do it, is to backspace through the text that I want to omit. I'd like to know if there's an easier way to do it. Anyone?

"Ah, but it was so much easier when I was cruel".
Elvis Costello