Code:
<script type="text/javascript">
    var scrolling = null;
 
    function scroll_left() {
        var d = document.getElementById('scroller');
 
        d.scrollLeft = d.scrollLeft - 5;
 
        scrolling = window.setTimeout(function() {
            scroll_left();
        }, 20);
    }
 
    function scroll_right() {
        var d = document.getElementById('scroller');
...