// JavaScript Document
function formatNum(expr,decplaces) {
	var str = (Math.round(parseFloat(expr) *
	Math.pow(10,decplaces))).toString()
	while (str.length <= decplaces) {
	str = '0' + str
	}
	var decpoint = str.length - decplaces
	return str.substring(0,decpoint) + '.' +
	str.substring(decpoint,str.length);
}