I am trying to use an image as a background to my links to make them look like buttons. I have got background images working elsewhere but when I specify one for the link it never appears. The css I am using is:

#nav a:link, #nav a:visited {
background-image: url(/images/nrdbutton_lrg2.gif); */

#nav a:hover {
background-image: url(/images/nrdbutton_lrg2.gif);


#nav #nav a:active {
background-image: url(/images/nrdbutton_lrg_down.gif);

Can anybody tell me what I am doing wrong?