.PDF file

[Gman]

If you click on "Go Advanced" in the lower right rather than just posting a quick reply, you'll see an icon in the toolbars that has a paperclip where you can create attachments.

ETA: I've never done what you're asking, nor do I know that the forum software/settings will allow PDF file types to be attached. Just stating how I think the mechanics of how I would attempt to get an attachment into a post would work.