格式化输出货币

 function formatCurrency(num)//格式化输出数字。。输出货币形式
 {
    // Courtesy of http://www7.brinkster.com/cyanide7/
  num = num.toString().replace(//$|/,/g,'');
  if(isNaN(num))
     num = "0";
  sign = (num == (num = Math.abs(num)));
  num = Math.floor(num*100+0.50000000001);
  cents = num%100;
  num = Math.floor(num/100).toString();
  if(cents<10)
      cents = "0" + cents;
  for (var i = 0; i < Math.floor((num.length-(1+i))/3); i++)
      num = num.substring(0,num.length-(4*i+3))+','+
            num.substring(num.length-(4*i+3));
       return (((sign)?'':'-') + '$' + num + '.' + cents);
 }