a.overlink{
    background-color:#ffffff;
    display:block;
}

a.overlink:hover img{
    cursor:pointer;
    filter: alpha(opacity=60);        /* ie lt 8 */
    -ms-filter: "alpha(opacity=60)";  /* ie 8 */
    -moz-opacity:0.6;                 /* FF lt 1.5, Netscape */
    -khtml-opacity: 0.6;              /* Safari 1.x */
    opacity:0.6;
    zoom:1;
}