function zenkakuToHankaku(zenStr) {
  var hankaku = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789@-----_.";
  var zenkaku = "£á£â£ã£ä£å£æ£ç£è£é£ê£ë£ì£í£î£ï£ð£ñ£ò£ó£ô£õ£ö£÷£ø£ù£ú£Á£Â£Ã£Ä£Å£Æ£Ç£È£É£Ê£Ë£Ì£Í£Î£Ï£Ð£Ñ£Ò£Ó£Ô£Õ£Ö£×£Ø£Ù£Ú£°£±£²£³£´£µ£¶£·£¸£¹¡÷¡½¡¼-¡ÝŽ°¡²¡¥";
  var hanStr = "";
  for (i = 0; i < zenStr.length; i++) {
    c = zenStr.charAt(i);
    n = zenkaku.indexOf(c,0);
    if (n >= 0) c = hankaku.charAt(n);
    hanStr += c;
    }
  return hanStr;
}
