var mainprice = 79.99;
var upsellprice = 19.99;
var installprice = 6.95;
var rebateprice = 30.00;

function updateMainPriceDisplay()
	{
		var qty = document.getElementById('mainqty');
		var price = document.getElementById('maindisplayprice');
		//var rprice2 = document.getElementById('rebateprice2');
		
		var intqty = parseInt(qty.value);
		if (intqty == 0) {
			price.innerText = " ";
			price.textContent = " ";
		}
		else {
			price.innerText = formatCurrency(mainprice*intqty);
			price.textContent = formatCurrency(mainprice*intqty);
		}
		//rprice2.innerText = formatCurrency(rebateprice*intqty);
		updateTotalPriceDisplay()
	}

function updateUpsellPriceDisplay()
	{
		var qty = document.getElementById('upsellqty');
		var price = document.getElementById('upselldisplayprice');
		var intqty = parseInt(qty.value);
		if (intqty == 0) {
			price.innerText = " ";
			price.textContent = unescape(" ");
			//price.innerHtml = " Hello";
		}
		else {
			price.innerText = formatCurrency(upsellprice*intqty);
			price.textContent = formatCurrency(upsellprice*intqty);
		}
		updateTotalPriceDisplay();
	}
	
function updateinstallPriceDisplay()
	{
		var qty = document.getElementById('installqty');
		var price = document.getElementById('installprice');
		var intqty = parseInt(qty.value);
		if (intqty == 0) {
			price.innerText = " ";
			price.textContent = unescape(" ");
			//price.innerHtml = " Hello";
		}
		else {
			price.innerText = formatCurrency(installprice*intqty);
			price.textContent = formatCurrency(installprice*intqty);
		}
		updateTotalPriceDisplay();
	}
	
function updateTotalPriceDisplay()
	{
		var mainqty = document.getElementById('mainqty');
		var upsellqty = document.getElementById('upsellqty');
		var installqty = document.getElementById('installqty');
		var price = document.getElementById('totaldisplayprice');
		var intmainqty = parseInt(mainqty.value);
		var intupsellqty = parseInt(upsellqty.value);
		var intinstallqty = 0
		if (installqty != null) {
			intinstallqty = parseInt(installqty.value);
		}
		if (mainqty == 0) {
			price.innerText = " ";
			price.textContent = " ";
		}
		else {
			price.innerText = formatCurrency(mainprice*intmainqty + upsellprice*intupsellqty + installprice*intinstallqty - rebateprice);
			price.textContent = formatCurrency(mainprice*intmainqty + upsellprice*intupsellqty + installprice*intinstallqty - rebateprice);
		}
	}
			
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);
}