JS :: Format a number

numberFormat.js

	/**
	 * Formats numbers (or string numbers)
	 * @param number	int or int-parsable string
	 * @param prec		decimal precision
	 * @returns			formatted number as string
	 */
	numberFormat : function (number, prec) {
		var ext, name, numS, rgx = /(\d+)(\d{3})/;
		number = number || '0';
		prec = prec || 0;
		numS = ('' + number).split('.');
		name = numS[0];
		ext = numS[1];
		if (prec > 0) ext = ((ext || '') + new Array(prec + 1).join('0')).substr(0, prec);
		else ext = '';
		while (rgx.test(name)) name = name.replace(rgx, '$1' + ',' + '$2');
		return name + (ext ? '.' + ext : '');
	},