oad() {
                addHandlers(document.getElementById('nameColumnHeader'), 0);
                addHandlers(document.getElementById('sizeColumnHeader'), 1);
                addHandlers(document.getElementById('dateColumnHeader'), 2);
            }

            window.addEventListener('DOMContentLoaded', onLoad);
        </script>

        <style>

            h1 {
                border-bottom: 1px solid #c0c0c0;
                margin-bottom: 10px;
                padding-bottom: 10px;
               