.index-wall-left {
    width: 249px;
    height: 160px;
    position: absolute;
    top: 420px;
    margin-left: 366px;
    background: url(http://www.b170.com/C_Images/duilian001.gif) no-repeat right top;
    background-size: contain;
    z-index: 10;
}
.index-wall-right {
    width: 249px;
    height: 160px;
    position: absolute;
    top: 420px;
    margin-left: 1140px;
    background: url(http://www.b170.com/C_Images/duilian001.gif) no-repeat left top;
    background-size: contain;
    z-index: 10;
}
.index-wall-fixed {
    position: fixed;
}