ok, you click reply on somones post, type what u gotta type, then tick the box that says "I want to preview my post and/or attach a file", then click continue, then a little box up the top will appear and it will say underneath "You may attach a file if you like (no bigger than 100000 bytes please). ", click browse, find the pic then click Ok, submit!
then a picture will show up like this one has /ubbthreads/images/graemlins/wink.gif
i hope that solved your problem