Simple Overscroll html structure

gistfile1.html

<div id="thumb_popout">
    <div id="scroll_wrapper">
        <div id="thumbnails_wrapper" style="width: 1815px;">
            <ul>
                <li><img src="img/dev/birds1.jpeg"></li>
                <li><img src="img/dev/birds2.jpeg"></li>
                <li><img src="img/dev/bridge1.jpeg"></li>
                <li><img src="img/dev/bridge2.jpeg"></li>
            </ul>
        </div>
    </div>
</div>