Putting the VAT (Sales Tax) on an order form

We used to be able to use the code below to add VAT onto the order form on the first page, so that people could see the entire price not net.

However this has stopped working. Now I’m no coding guru in the slightest, can anyone either see why they think it stopped working and/or if anyone has a different solution (that is still IS order forms).

Edit: I’ve removed the opening < and closing > as the boards won’t post it otherwise!

script type=“text/javascript”>
// to trigger IS to include the tax value from the start.
// adds text to the zipcode, city and addressline1 fields
// creates an event to trigger IS to do it’s thing
// remove the text from the fields
zipCode = document.getElementById(“zipCode”);
city = document.getElementById(“city”);
addressLine1 = document.getElementById(“addressLine1”);

zipCode.value = “1”;
city.value = “1”;
addressLine1.value = “1”;

element = zipCode;
if (“fireEvent” in element)
var evt = document.createEvent(“HTMLEvents”);
evt.initEvent(“change”, false, true);

zipCode.value = “”;
city.value = “”;
addressLine1.value = “”;