var base_dir = "/modx/assets/templates/default/";

function rollover(button_id) {
  document.getElementById(button_id).style.backgroundImage = "url("+base_dir+"images/image_buttonBG_over.jpg)";
}

function rollout(button_id) {
  document.getElementById(button_id).style.backgroundImage = "url("+base_dir+"images/image_buttonBG.jpg)";
}