.mask {
    z-index: 499;
    display: none;
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    overflow: auto;

    background-color: #000;
    opacity: .25;
* filter : alpha ( opacity = 25 );
}


.floating-pane{
    border: 3px solid #000000;
    background-color:#f1f3eb;
    position:absolute;
    display:none;
    z-index:500;
* zoom : 1;
}