members cannot delete posts. we learned several years ago that it can lead to abuse, confusion and headaches for everybody.
there is absolutely no need to feel like an idiot if you accidentally double-post. it happens for a lot of reasons, most of which don't have anything to do with the user's level of intelligence.
usually, it's because the browser hangs up and we think the post didn't go through. we do the naturally human thing and click the "send" button again. i've seen triple posts. i've received up to four copies of the same pm.
it's no big deal.