ul.ContextMenu {
    list-style-type: none;
    margin: 0;
    padding: 0;
    width: 300px;
    position: absolute;
    z-index: 9999;
    max-height: 600px;
    overflow: auto;
}

ul.ContextMenu li {
    display: block;
    color: #000;
    background-color: #c5c5c5;
    padding: 6px 0 6px 6px;
    text-decoration: none;
    cursor:pointer;
}

ul.ContextMenu li:hover {
    background-color: #999;
    color: white;
}