/* 
just add  

onChange="this.value = format_currency(this.value,'places');"

to your input to format as a dollar
*/


function formatCurrency(num) {
num = num.toString().replace(/[^0-9\.]/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);
}

function format_currency(num,places) {
	num = num.toString().replace(/[^0-9\.]/g,'');
    num = isNaN(num) || num === '' || num === null  ? 0.00 : num;
    num = parseFloat(num).toFixed(places);
	return '$'+num;
}