var  aTens = [ "TWENTY", "THIRTY", "FORTY", "FIFTY", "SIXTY", "SEVENTY", "EIGHTY", "NINETY"];

var 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) ? "" : "";

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+'ONLY';

}

调用：
ConvertToWords(123,450,000.66) -->ONE HUNDRED AND TWENTY THREE MILLION FOUR HUNDRED AND FIFTY THOUSAND SIXTY SIX CENTS ONLY