It may be possible to hide the “X” (set it to the same color as the background, or make it “visibility:hidden”, etc.). Then include your own image inside the main infobox body and use position: to position it in the corner.
Hi Chris, thank you for the feedback. I was trying to avoid creating duplicate CSS classes just to cover for the links, because I’m intending to use the buttons I already have. Concerning the “X” I think it could be really useful to be able to define what one wants there. Regards