Flickr seems much tougher to figure out than Photobucket. Once your photo is uploaded to Flickr, click on the 'Share' button (curved up to right arrow icon) at the bottom. In the Pop up box, choose BBCode
and the size of the photo you wish to display. Then COPY the code in the box below the size box.
Back to your forum message, click on the 'PHOTO' icon (yellow box w/mountain and sun) In the pop up window, PASTE the code copied from the Flickr box. That should do it.
, on Flickr