Number to word in indian format

I have the following script :

aTens = [ "Twenty", "Thirty", "Forty", "Fifty", "Sixty", "Seventy", "Eighty", "Ninety"];

aOnes = [ "Zero", "One", "Two", "Three", "Four", "Five", "Six", "Seven", "Eight", "Nine",

"Ten", "Eleven", "Twelve", "Thirteen", "Fourteen", "Fifteen", "Sixteen", "Seventeen", "Eighteen",

"Nineteen" ];

function ConvertToHundreds(num)

{

var cNum, nNum;

var cWords = "";

num %= 1000;

if (num > 99) {

/* Hundreds. */

cNum = String(num);

nNum = Number(cNum.charAt(0));

cWords += aOnes[nNum] + " Hundred";

num %= 100;

if (num > 0)

cWords += " and "

}

if (num > 19) {

/* Tens. */

cNum = String(num);

nNum = Number(cNum.charAt(0));

cWords += aTens[nNum - 2];

num %= 10;

if (num > 0)

cWords += "-";

}

if (num > 0) {

/* Ones and teens. */

nNum = Math.floor(num);

cWords += aOnes[nNum];

}

return cWords;

}

function ConvertToWords(num)

{

var aUnits = [ "Thousand", "Million", "Billion", "Trillion", "Quadrillion" ];

var cWords = (num >= 1 && num < 2) ? "Dollar and " : "Dollars and ";

var nLeft = Math.floor(num);

for (var i = 0; nLeft > 0; i++) {

if (nLeft % 1000 > 0) {

if (i != 0)

cWords = ConvertToHundreds(nLeft) + " " + aUnits[i - 1] + " " + cWords;

else

cWords = ConvertToHundreds(nLeft) + " " + cWords;

}

nLeft = Math.floor(nLeft / 1000);

}

num = Math.round(num * 100) % 100;

if (num > 0)

cWords += ConvertToHundreds(num) + " Cents";

else

cWords += "Zero Cents";

return cWords;

}

This script works perfectly for US number system........but i want this in Indian Number system

like :  50,000 is Fifty Thousand

          5,00,000  is Five Lakhs

         50,00,000 is Fifty Lakhs

         5,00,00,000 is Five crores     i.e     instead of         [ "Thousand", "Million", "Billion", "Trillion", "Quadrillion" ]

                                                                      i want         ["Thousand", "Lakhs", "Crores"]

Thanks.