i have this one and dont know what is wrong with my script please help me figure it out

<html>
<head>
<title>Duncan's Just-In-Time Donut</title>
<link rel="stylesheet" type="text/css" href="donuts.css" />
<script type="text/javascript">
function updateOrder() {
const TAXRATE = 0.0925;
const DONUTPRICE = 0.50;
var numCakeDonuts = parseInt(document.getElementById("cakedonuts").value);
var numGlazedDonuts = parseInt(document.getElementById("glazeddonuts").value);
if (isNaN(numCakeDonuts)) {
numCakeDonuts = 0;
}
if (isNaN(numGlazedDonuts)){
numGlazedDonuts = 0;
}
var subTotal = (numCakeDonuts + numGlazedDonuts) * DONUTPRICE;
var tax = subTotal * TAXRATE;
var total = subTotal + tax;
document.getElementById("fieldSubTotal").value = "$" + subTotal.toFixed(2);
document.getElementById("fieldTax").value = "$" + tax.toFixed(2);
document.getElementById("fieldTotal").value = "$" + total.toFixed(2);
}
function placerOrder() {
if (document.getElementById("customername").value=="")
Alert("I'm sorry but you must provide your name before submitting an order.");
else if(document.getElementById("pickupminutes").value=="")||
isNaN(document.getElementById("pickupminutes").value))
Alert("I'm sorry but you must provie the number of minutes until pick-up" +
" before submitting an order.");
else
// Submit order to server...
form.submit();
}
</script>
</head>
<body>
<div id="frame">
...
<form name="orderform" action="donut.php" method="POST">
<div class="field">
Name: <input type="text" id="customerName" name="customerName"
value="" onchange=""/>
</div>
<div class="field">
# of cake donut: <input type="text" id="cakedonut" name="cakedonut"
Value="" onchange="updateOrder();" />
</div>
<div class="field">
# of glazed donut: <input type="text" id="glazeddonuts" name="glazeddonuts"
value="" onchange="updateOrder();" />
</div>
<div class="field">
Minutes to Pickup: <input type="text" id="minutes" name="minutes"
value="" onchange=""/>
</div>
<div class="field">
Subototal: <input type="text" id="fieldSubTotal" name="fieldSubTotal"
value="" onchange="" readonly="readonly"/>
</div>

<div class="field">
Tax: <input type="text" id="fieldTax" name="fieldTax"
value="" onchange="" readonly="readonly"/>
</div>

<div class="field">
Total: <input type="text" id="fieldTotal" name="fieldTotal"
value="" onchange="" readonly="readonly"/>
</div>
<div class="field">
<input type="button" value="Place Order"
onclick="placeOrder(this.form);" />
</div>
</form>
</div>
</body>
</html>