$(document).ready(function(){
	$("#bulbselect").change(function(){
		bulbcalc();
	});
	
	$("#numbulbs").change(function(){
		bulbcalc();
	});
});

//http://www.standardpro.com/environment/energysavingcalculator.aspx - assume $.10/kwh 

function bulbcalc()
{
	var watt = $("#bulbselect").val();
	var lifetime = 0;
	if (watt == "40") lifetime = 24.80;
	if (watt == "60") lifetime = 47;
	if (watt == "75") lifetime = 60;
	if (watt == "100") lifetime = 77;
	var annualsavings = lifetime * $("#numbulbs").val() * .13;
	var totalsavings = lifetime * $("#numbulbs").val();
	
	$("#bulb_annualsavings").text(formatCurrency(annualsavings)); // 3 hrs per day with 8000 hr lifetime
	$("#bulb_totalsavings").text(formatCurrency(totalsavings));	
}

function formatCurrency(num) {
num = num.toString().replace(/\$|\,/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);
}