function ccRollover(e) {
  var imgDir = subDir + '/images/content/';
  listen(document.getElementById('contactUs'), imgDir + 'contactUs0.gif', imgDir + 'contactUs1.gif');
}

if (window.addEventListener) {
  window.addEventListener('load', ccRollover, false);
} else if (window.attachEvent) {
  window.attachEvent('onload', ccRollover);
} else if (window.onload) {
  window.onload = ccRollover;
}