function comicChange(factor) {
  var archiveDir = 'comics/';
  var commonHeight = '1035';
  var archive = document.getElementById('archive');
  var current = archive.selectedIndex;
  if (factor == 'first') var factor = 0;
  else if (factor == 'last') var factor = archive.length - 1;
  else if (factor == undefined) var factor = current;
  else var factor = current + factor;
  if (archive[factor]) {
    scroll(0, 420);
    var comic = document.getElementById('comic2');
    comic.innerHTML = 'Loading...';
    comic.style.lineHeight = commonHeight+'px';
    var newComic = document.createElement('img');
    newComic.alt = document.getElementById('comicTitle').innerHTML = archive[factor].innerHTML;
    newComic.onload = function () {
      archive.selectedIndex = factor;
      comic.innerHTML = '';
      comic.style.lineHeight = '1.2em';
      comic.appendChild(newComic);
    }
    newComic.src = archiveDir+archive[factor].title;
  }
}