.banner {
    width: 1024px;
    position: relative;
    margin-bottom: 15px;
}

.banner,
.banner ul {
    display: block;
    height: 500px;
    overflow: hidden;
}

.banner li,
.banner li a,
.banner li a img {
    display: block;
    width: 1024px;
    height: 500px;
    float: left;
    overflow: hidden;
}

.banner #prevbt,
.banner #nextbt {
    display: block;
    width: 30px;
    height: 50px;
    background: url(../style/indexsprites.png) no-repeat #fff;
    position: absolute;
    top: 350px;
    opacity: .3;
    filter: alpha(opacity=30);
}

.banner #prevbt {
    background-position: 0 -110px;
    left: 0;
    border-top-right-radius: 5px;
    border-bottom-right-radius: 5px;
}

.banner #nextbt {
    background-position: -40px -110px;
    right: 0;
    border-top-left-radius: 5px;
    border-bottom-left-radius: 5px;
}