.popup {
    position: absolute;
    display: block;
    overflow: hidden;
    left: -300px;
    font-family: arial,verdana,helvetica,lucida,sans-serif;
    font-size: 90%;
    text-align: left;
    border: 1px solid black;
    padding: 2px;
    background-color: lightyellow;
    visibility: hidden;
    z-index: 100;
    filter: progid:DXImageTransform.Microsoft.Shadow(color=gray,direction=135,strength=2);
}
.arrow {
    position: absolute;
    height: 15px;
    width: 8px;
    left: -300px;
    visibility: hidden;
    z-index: 101;
}