function currency_format(str) {
	var newStr = '';
	var index = 0;
	str = str.toString();
	
	while (index < str.length) {
		if (index > 0 && index % 3 == 0) {
			newStr = ',' + newStr;
		}
		newStr = str.charAt(str.length - index - 1) + newStr;
		index++;
	}
	return newStr;
}		

function calcAmount(amount) {
	var arr = new Array();
	var index = 0;
	var str = 'rate_' + index;
	while (document.getElementById(str) != null && document.getElementById(str) != 'undefined') {
		arr[index] = document.getElementById(str).innerHTML;
		index++;
		str = 'rate_' + index;
	}
	
	for (i = 0; i < arr.length; i++) {
		var temp = Math.round(amount / arr[i]);
		var temp = temp.toString();
		str = 'amount_' + i;
		document.getElementById(str).innerHTML = currency_format(temp);
	}
}