I have been updating a web payment form and have run into some trouble.

The original form is here if you want to look at it - http://mk18.web44.net/#order

I have updated it to make the advert easier to select and choose how many issues are needed.

You can see the new form here - http://mk18.web44.net/index3.php#order

I have started updating the JavaScript code and this is where the problem is.

I have put the new values of the advert field into the js code along with the price of 1 issue. I have also put in the code that works out the new price based on how many issues are selected.

The problem is that the prices dont update on the form.

Can you help me with this . The JS code can be viewed bellow of by right clicking in the index3.php page.

JS Code :

Code:
function formatPrice(theField){

  if(isNaN(theField.value)){

    theField.select();

    theField.focus();

    alert('Invalid price: '+theField.value);

    return false;

  }

  price = Math.round(100+theField.value*100)+'';

  theField.value = parseInt((price-100)/100)+'.'+price.substr(price.length-2);

}

function calculate() {

adcharge = 0;

designcharge = 0;

thetotal = 0;

vatrate = 0.20;

cardfee = 0;

grand_total = 0;

issue =  0;

var money = grand_total;

if (document.getElementById('advert').value == "FullPage" {adcharge = 188;}
if (document.getElementById('advert').value == "HalfPage" {adcharge = 200;}
if (document.getElementById('advert').value == "QuarterPage" {adcharge = 245;}
if (document.getElementById('advert').value == "EighthPage" {adcharge = 288;}

document.getElementById('ad_charge').value = adcharge;

formatPrice(document.getElementById('ad_charge'));

switch(document.getElementById('issues').value) {
    case 2:
        adcharge *= 2;
        adcharge *= 0.9; 
        break;
    case 3:
        adcharge *= 3;
        adcharge *= 0.85;
        break;
    case 6:
        adcharge *= 6;
        adcharge *= 0.85;
        break;
 }


if (document.getElementById('design_service').checked == true){designcharge = 20;}

document.getElementById('design_charge').value = designcharge;

formatPrice(document.getElementById('design_charge'));



document.getElementById('sub_total').value = adcharge + designcharge;

formatPrice(document.getElementById('sub_total'));



thetotal = adcharge + designcharge;



document.getElementById('vat').value = thetotal * vatrate;

formatPrice(document.getElementById('vat'));



document.getElementById('total').value = thetotal * (1 + vatrate);

formatPrice(document.getElementById('total'));



if (document.getElementById('payment_method').value == "PayPal") {cardfee = ((thetotal * (1 + vatrate)) * 0.024)+0.24;}

document.getElementById('card_fee').value = cardfee;

formatPrice(document.getElementById('card_fee'));



document.getElementById('grand_total').value = (thetotal * (1 + vatrate)) + cardfee;

formatPrice(document.getElementById('grand_total'));

return true;

}