function NumFormatter(){
  this.decimal_regex = /(\d+)\.(\d+)/;

  this.comma_format = function(int_num)
  {
    var arg_type = (typeof int_num); //xxx

    if( arg_type == "string" )
    {
      var num_str = int_num;
    }
    else if(arg_type == "number")
    {
      var num_str = int_num + "";
    }

    var len = num_str.length;
    var r = "";
    var j = 1;

    var decimal_point_index = num_str.indexOf(".");
    var starting_point_index = len - decimal_point_index - 1;

    for( var i = len-1; i >= 0 ; i-- )
    {
      var char_candidate = num_str.charAt(i);
      if (j % 3 == 0)
      {
        if( i != 0 )
          r = "," + char_candidate + r;
        else
          r = char_candidate + r;
      }
      else
      {
        r = char_candidate + r;
      }// else

      if( decimal_point_index == -1)
      {
        // doesn't have decimal
        j++;
      }
      else
      {
        // deal with decimal
        if((len - 1 - i) > starting_point_index)
        {
          j++;
        }
      }
    }// for

    return r;
  };

  this.format_decimal = function(float_num, decimal_places)
  {
    if(float_num == "Undefined")
    {
      return float_num;
    }
    else if(float_num == "N/A")
    {
      return "---";
    }
    else
    {
      var decimal_place_num = Math.pow(10,decimal_places);

      var r_str = String(Math.round(float_num*decimal_place_num)/decimal_place_num);
      var r_reg = this.decimal_regex.exec(r_str);
      var padded_zeros = decimal_places;
      // r_reg is null if float_num doesn't have a decimal point in it. like 1 instead of 1.0
      if(r_reg != null)
      {
	padded_zeros -= r_reg[2].length;
      }
      else
      {
	r_str += ".";
      }

      for(var i = 0; i <padded_zeros; i++)
      {
	r_str += "0";
      }
      return r_str;
    }
  };
}