var keta_str2 = ":万億兆京".match(/./g);

  //桁考慮あり
  function num2kanji(val){
    var kanji_str = ":一二三四五六七八九".match(/./g);
    var keta_str  = ":十百千".match(/./g);
    var keta_str2 = ":万億兆京".match(/./g);
    var i,j;
    if (val==0) return "零";
    val = val+"";
    val = val.match(/./g).reverse().join("");
    val = val.replace(/(\d{4})/g,"$1,").replace(/\,$/,"").split(",");
    for (i=0;i<val.length;i++){
      var str = "";
      for (j=val[i].length-1;0<=j;j--){
        str += kanji_str[val[i].charAt(j)] + keta_str[j];
      }
      str = str.replace(/:./g,"")+keta_str2[i];
      if (str.length==1) str="";
      val[i] = str.replace(/:/g,"");
      val[i] = val[i].replace(/一(百)|一(十)/g,"$1$2");
    }
    val = val.reverse().join("");
    return val;
  }
  
  //桁考慮なし
  function num2kanji2(val){
    var kanji_str = "〇一二三四五六七八九".match(/./g);
    val = val + "";
    val = val.replace(/(.)/g,"kanji_str[$1]+").replace(/\+$/,"");
    return eval(val);
  }