Gallerie - Problem mit den Codes

.main_image {
    width: 598px;
    height: 456px;
    float: left;
    background: #333;
    position: relative;
    overflow: hidden; /*--Overflow hidden allows the description to toggle/tuck away as it slides down--*/
    color: #fff;
}
.main_image h2 {
    font-size: 2em;
    font-weight: normal;
    margin: 0 0 5px;
    padding: 10px;
}
.main_image p {
    font-size: 1.2em;
    line-height: 1.6em;
    padding: 10px;
    margin: 0;
}
.block small { /*--We'll be using this same style on our thumbnail list--*/
    font-size: 1em;
    padding: 0 0 0 20px;
    background: url(icon_calendar.gif) no-repeat 0 center;
}
.main_image .block small {margin-left: 10px;}
.main_image .desc{
    position: absolute;
    bottom: 0;
    left: 0; /*--Stick the desc class to the bottom of our main image container--*/
    width: 100%;
    display: none; /*--Hide description by default, if js is enabled, we will show this--*/
}
.main_image .block{
    width: 100%;
    background: #111;
    border-top: 1px solid #000;
}
.main_image a.collapse { /*--This is our hide/show tab--*/
    background: url(btn_collapse.gif) no-repeat left top;
    height: 27px;
    width: 93px;
    text-indent: -99999px;
    position: absolute;
    top: -27px;
    right: 20px;
}
.main_image a.show {background-position: left bottom;}

.image_thumb {
    float: left;
    width: 299px;
    background: #f0f0f0;
    border-right: 1px solid #fff;
    border-top: 1px solid #ccc;
}
.image_thumb img {
    border: 1px solid #ccc;
    padding: 5px;
    background: #fff;
    float: left;
}
.image_thumb ul {
    margin: 0;
    padding: 0;
    list-style: none;
}
.image_thumb ul li{
    margin: 0;
    padding: 12px 10px;
    background: #f0f0f0 url(nav_a.gif) repeat-x;
    width: 279px;
    float: left;
    border-bottom: 1px solid #ccc;
    border-top: 1px solid #fff;
    border-right: 1px solid #ccc;
}
.image_thumb ul li.hover { /*--Hover State--*/
    background: #ddd;
    cursor: pointer;
}
.image_thumb ul li.active { /*--Active State--*/
    background: #fff;
    cursor: default;
}
html .image_thumb ul li h2 {
    font-size: 1.5em;
    margin: 5px 0;
    padding: 0;
}
.image_thumb ul li .block {
    float: left;
    margin-left: 10px;
    padding: 0;
    width: 170px;
}
.image_thumb ul li p{display: none;}/*--Hide the description on the list items--*/

<div class="main_image">
    <img src="banner1.jpg" alt="" />
    <div class="desc">
        <a href="#" class="collapse">Close Me!</a>
        <div class="block">
            <h2>Title</h2>
            <small>Date</small>
            <p>Copy</p>
        </div>
    </div>
</div>
<div class="image_thumb">
    <ul>
        <li>
            <a href="banner1.jpg"><img src="banner1_thumb.jpg" alt="Image Name" /></a>
            <div class="block">
                <h2>Title</h2>
                <small>Date</small>
                <p>Copy</p>
            </div>
        </li>
    </ul>
</div>