a.screen2, a.screen2:visited {
color:#ffffff; 
position:center; 
z-index:1;
}
a.screen2 b {
position:absolute;
visibility:hidden; /* hide the image */
width:360px; /* give it a width */
height:0; /* no height to solve an Opera bug that 
             makes it selectable when hidden */
border:2px solid #000; /* add a border */
padding: 5px 5px 5px 5px;
background: #FFFFFF;
left:0%; /* position:the image */
top:40%;
}
a.screen2:hover {
color:; 
text-decoration:none; 
border:0; /* needed for this to work in IE */ 
z-index:1000;
}
a.screen2:hover b {
visibility:visible; /* make the image visible */
height:480px; /* now give it a height */
cursor:pointer; /* for IE */
z-index:500; 
}
a.screen2:hover b img {
border:0; /* remove the link border */