#primary-nav li a  {
display: block;
height: 33px;
color: #000;
background-image:url(http://www.pennmedicine.org/social-media/images/primary-nav.gif);
text-indent: -9876px;
}

#pn-1 {
width: 110px;
left: 0;
}
#pn-2 {
width: 140px;
left: 110px;
}
#pn-3 {
width: 239px;
left: 250px;
}
#pn-4 {
width: 136px;
left: 489px;
}
#pn-5 {
width: 135px;
left: 625px;
}
#pn-6 {
width: 140px;
left: 760px;
}
#pn-1 a:link, #pn-1 a:visited {
background-position: 0 0;
}
#pn-2 a:link, #pn-2 a:visited {
background-position: -110px 0;
}
#pn-3 a:link, #pn-3 a:visited {
background-position: -250px 0;
}
#pn-4 a:link, #pn-4 a:visited {
background-position: -489px 0;
}
#pn-5 a:link, #pn-5 a:visited {
background-position: -625px 0;
}
#pn-6 a:link, #pn-6 a:visited {
background-position: -760px 0;
}
#pn-1 a:hover {
background-position: 0px -33px;
}
#pn-2 a:hover {
background-position: -110px -33px;
}
#pn-3 a:hover {
background-position: -250px -33px;
}
#pn-4 a:hover {
background-position: -489px -33px;
}
#pn-5 a:hover {
background-position: -625px -33px;
}
#pn-6 a:hover {
background-position: -760px -33px;
}
#home #pn-1 a:visited {
background-position: 0px -66px;
}
#patient #pn-2 a:visited {
background-position: -110px -66px;
}
#healthpro #pn-3 a:visited {
background-position: -250px -66px;
}
#education #pn-4 a:visited {
background-position: -489px -66px;
}
#research #pn-5 a:visited {
background-position: -625px -66px;
}
#about #pn-6 a:visited {
background-position: -760px -66px;
}