the first thing is save the picture as a file on your computer.
on windows, press print screen then open paint, paste it in and save it.
on a mac, press command-shift-3 and it'll save to the desktop.
on desktop linux, use whatever screenshot program you have.
then upload the file to somewhere on the internet.
then when you're on post reply, use 'Img' and type the URL of wherever you put the photo.
<div align=\"center\"> - i.n.s - </div>