/*
 * 決済実行ボタンを無効にする。
 */
function disable_settlement_submit(elem, image_path) {
  elem.setAttribute('originalValue', elem.value);
  elem.disabled = true;
  document.getElementById(elem.id).src = image_path;
  result = (elem.form.onsubmit ? (elem.form.onsubmit() ? elem.form.submit() : false) : elem.form.submit());
  if (result == false) { 
    elem.disabled = false;
  } 
  return result;
}