comma_format_number.js

function comma_format_number (value) {
	value = value.replace(/,/g, '');

	var lead = value.length % 3;

	var lead_segment = value.substring(0, lead);
	value = value.substring(lead, value.length);
	value = value.match(/(\d{3})/g);

	if (value != null && value.length > 0) {
		value = value.join(',');

		if (lead_segment.length > 0) {
			value = lead_segment + ',' + value;
		};				
	} else {
		value = lead_segment;
	}

	return value;
}