function writeHEADERtop(){
 nowTime = new Date();
 nowHour = nowTime.getHours();
if ((nowHour >= 18) || (nowHour <= 5)){
  document.write("<img src='/img/main_photo_nighttime.jpg' width='880' height='433' alt='雷門 Kaminarimon'>");}
if ((nowHour >= 6) && (nowHour <= 17)){
  document.write("<img src='/img/main_photo_daytime.jpg' width='880' height='433' alt='雷門 Kaminarimon'>");}
}