.ad-right, .ad-left{
    position: fixed;
    z-index: 1;
    top: 220px;
    width: 120px;
    height: 300px;

    _position: absolute;
    _z-index: 10;
    _top: expression(documentElement.scrollTop + 220 + "px");
}
.ad-right{
    right: 0px;
}
.ad-left{
    left: 0px;
}
.ad-btn-close{
    display: block;
    position: absolute;
    text-align: center;
    width: 1.2em;
    height: 1.2em;
    line-height: 1.2em;
    bottom: -1.2em;
    cursor: pointer;
    color: white;
    background-color: #98c94b; 
    border: 1px solid #eee;
}