Go to your photo account and open the picture you want to post.
Right click on it. Go down to where it says "Properties" and left-click on it. In the window that opens up, copy the part that says "Address: (URL)"
Open your reply window here. Click on the little "tree" icon at the top of it, next to the smilie face.
Put you cursor in the little window at the top and backspace out the "http://" that's in there.
Right-click in the little window and select "paste". THe URL will appear in there. Then left click on the "Insert" button at the bottom of the reply window. You'll see the URL appear in the field with the "Image" commands at each end. It'll look kinda like this:
Keep in mind that you MUST remove the "http://" from the window at first. You can only have ONE "http://" in the URL address in the reply window.
Click "Preview" to check your work.
Then either click "edit" to return to the reply window, or "Post" if you're done...