// For use with express delivery checkbox on webshop
function changeShipping(price) {
	var checked=document.getElementById("express").checked;
	var formTag =document.getElementsByName("shipping")[0];
	if(checked) {
		shipping = parseFloat(formTag.value) + price;
		formTag.value = shipping;
	}
	else {
		shipping = parseFloat(formTag.value) - price;
		formTag.value = shipping;
	}
}

function subtractShipping(price) {
	var checked=document.getElementById("express").checked;
	var formTag =document.getElementsByName("shipping")[0];
	if(checked) {
		shipping = parseFloat(formTag.value) - price;
		formTag.value = shipping;
	}
	else {
		shipping = parseFloat(formTag.value) + price;
		formTag.value = shipping;
	}
}