"opacity: 0;" if you don't want to actually remove the box from the page "display: none;" if you do though as with all things CSS, tends to be a bit easier sa

"opacity: 0;" if you don't want to actually remove the box from the page "display: none;" if you do though as with all things CSS, tends to be a bit easier said than done (this is sort of a wild shot in the dark guessing at what you're talking about, but I've done a lot of CSS and it feels like a good guess)