Displaying an image in a lightbox
Looks fine to me, but I do have a few recommendations:

Instead of calling the onclick handler inline, consider doing the following:

$('#close').click(function(e) { fadeBox(e); });


Then I would pass e to fadeBox() and do e.preventDefault() so that the click event doesn't throw the user to the top of the page.

Also, you do not need to create the function hideLightBox() if the only thing it is doing is calling fadeBox().