Viewing the source code of your page page, I see the following:
<script language="javascript" type="text/javascript" />
<!--
function process3Shirts()
{
var quantity = parseInt(document.HSMLicense_BrassyHSM_BrassyHSM.txt3ShirtQuantity.value);
var unitPrice = parseFloat(document.HSMLicense_BrassyHSM_BrassyHSM.txt3ShirtUnitPrice.value);
var total = unitPrice * quantity;
document.HSMLicense_BrassyHSM_BrassyHSM.txt3ShirtTotal.value = total.toFixed(2);
}
</script>
there is a missing closing comment. it should be:
<script language="javascript" type="text/javascript" />
<!--
function process3Shirts()
{
var quantity = parseInt(document.HSMLicense_BrassyHSM_BrassyHSM.txt3ShirtQuantity.value);
var unitPrice = parseFloat(document.HSMLicense_BrassyHSM_BrassyHSM.txt3ShirtUnitPrice.value);
var total = unitPrice * quantity;
document.HSMLicense_BrassyHSM_BrassyHSM.txt3ShirtTotal.value = total.toFixed(2);
}
-->
</script>