ul li#wpub a {
background: transparent url(icon_wpub.gif) no-repeat top center;
}

ul li#wcon a {
background: transparent url(icon_wcon.gif) no-repeat top center;
}

ul li#wshr a {
background: transparent url(icon_wshr.gif) no-repeat top center;
}

ul li#wpst a {
background: transparent url(icon_wpst.gif) no-repeat top center;
}