超市购物结算

<script>
	function calculation() {
		var shampooPrice = parseInt(document.getElementById('shampoo').value);
		var instantNoodlesPrice = parseInt(document.getElementById('instantNoodles').value);
		var penPrice = parseInt(document.getElementById('pen').value);
		var totalPrice = shampooPrice + instantNoodlesPrice + penPrice;
		document.getElementById('totalPrice').value = totalPrice;

		var receivedMoney = 100;
		var change = receivedMoney - totalPrice;
		document.getElementById('change').value = change;
	}
</script>