To post Image from Photobucket.com:
1) From your photobucket album, click on the photo you wish to post, resize to 800x600, copy "Direct link".
2) From you VietJoy posting window, click on the "Img" box, paste the link in between.
If you haven't had an account with Photobucket, you can register for one at http://www.photobucket.com and upload your photos. It is really quick and easy.
You can also post image from other Photo sharing websites, using the same steps.