function formatAmount(amount)
{
  var elements = new String(amount).split(".");
  if(elements.length==2)
  {
    switch(elements[1].length)
    {
      case 1:
      return elements[0] + ',' +elements[1] + '0';
      case 2:
      return elements[0] + ',' +elements[1];
      break;
      default:
      return elements[0] + ',00';
      break;
    }
  }
  else
  {
    return elements[0] + ',00';
  }
}


function updateSum()
{
  var amount = 0.00;
  var hits = $("input[name^='order']");
  for(i=0;i<hits.length;i++)
  {
    hits[i].value = parseInt(hits[i].value);
    var qty = hits[i].value;
    var elements = hits[i].name.split("_");
    var id = elements[1];
    var price = $("input[name='price_"+id+"']")[0].value;
    amount += (qty*price);

    // update subtotals
    if(qty<=1)
      $("#itemamount_"+id).html('');
    else
      $("#itemamount_"+id).html('x'+qty+'&nbsp;=&nbsp;&euro;&nbsp;'+formatAmount(qty*price));
  }

  hits = $("input[name^='optorder']");
  for(i=0;i<hits.length;i++)
  {
    hits[i].value = parseInt(hits[i].value);
    var qty = hits[i].value;
    var elements = hits[i].name.split("_");
    var id = elements[1];
    var price = $("input[name='optprice_"+id+"']")[0].value;
    amount += (qty*price);

    // update subtotals
    if(qty<=1)
      $("#optitemamount_"+id).html('');
    else
      $("#optitemamount_"+id).html('x'+qty+'&nbsp;=&nbsp;&euro;&nbsp;'+formatAmount(qty*price));
  }

  $('#_sum')[0].innerHTML = formatAmount(amount);
}