function update_price(itemId, price)
{
  var newPrice = $('#select_item_'+itemId+' :selected').text() * price;
  $('#item_price_'+ itemId).text(Math.round(newPrice*100)/100);
  
  update_total(itemId); 
}

function delete_item(item)
{
  $('#'+ item).remove(); 
}

function update_total(itemId)
{
  var total = new Number(0);
  
  for(i = 1 ; i < 10; i++)
  {
    if($('#item_price_' + i).length > 0)
    {
      price = new Number(parseFloat($('#item_price_' + i).text())); 
      total = total + price;
    }
  }
  
  $('#total_price').text(Math.round(total*100)/100);
  porto = 2.3;
  var items = $('#select_item_'+itemId+' :selected').text();
  if(items > 1)
  {
    porto = 0;
  }
  if(porto == 0)
  {
    $('#porto').text('gratuit');
  }
  else
  {
    $('#porto').text(porto + ' €');
  }
  
  if($('#promo_value').length > 0)
  {
    var promoVal = new Number($('#promo_value').val());
    var promo = total * promoVal / 100;
    $('#total_promo').text('- ' + Math.round(promo*100)/100);

    total = total - promo + porto;
  }
  else
  {
    total = total + porto;
  }
  $('#total_order').text(Math.round(total*100)/100);

}