body {
 background: #000;
}

body div {
 display: none;
}
.alert {
 position: absolute;
 width: 555px;
 height: 450px;
 display: block !important;
 background: url(../images/ie6.jpg) 50% 50% no-repeat;
 left: 50%;
 top: 50%;
 margin: -250px 0 0 -250px;
 z-index: 100000;
}