function popupWindow(url) {
  window.open(url,'popupWindow','toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=yes,resizable=yes,copyhistory=no,width=400,height=300,screenX=150,screenY=150,top=150,left=150')
}

function checkForm() {
  var error = 0;
  var error_message = "Vyskytly se chyby během zpracování vašeho formuláře. Opravte následující položky:";

  var review = document.product_reviews_write.review.value;

  if (review.length < 10) {
    error_message = error_message + "* Text komentáře musí být alespoň 10 znaků dlouhý.";
    error = 1;
  }

  if ((document.product_reviews_write.rating[0].checked) || (document.product_reviews_write.rating[1].checked) || (document.product_reviews_write.rating[2].checked) || (document.product_reviews_write.rating[3].checked) || (document.product_reviews_write.rating[4].checked)) {
  } else {
    error_message = error_message + "* Musíte zboží ohodnotit.";
    error = 1;
  }

  if (error == 1) {
    alert(error_message);
    return false;
  } else {
    return true;
  }
}
var selected;

function selectRowEffect(object, buttonSelect) {
  if (!selected) {
    if (document.getElementById) {
      selected = document.getElementById('defaultSelected');
    } else {
      selected = document.all['defaultSelected'];
    }
  }

  if (selected) selected.className = 'moduleRow';
  object.className = 'moduleRowSelected';
  selected = object;

// one button is not an array
  if (document.checkout_address.address[0]) {
    document.checkout_address.address[buttonSelect].checked=true;
  } else {
    document.checkout_address.address.checked=true;
  }
}

function rowOverEffect(object) {
  if (object.className == 'moduleRow') object.className = 'moduleRowOver';
}

function rowOutEffect(object) {
  if (object.className == 'moduleRowOver') object.className = 'moduleRow';
}

function check_form_optional(form_name) {
  var form = form_name;

  var firstname = form.elements['firstname'].value;
  var lastname = form.elements['lastname'].value;
  var street_address = form.elements['street_address'].value;

  if (firstname == '' && lastname == '' && street_address == '') {
    return true;
  } else {
    return check_form(form_name);
  }
}

function addBookmark(title, url) {

	if (window.sidebar) { // Mozilla Firefox Bookmark
		window.sidebar.addPanel(title, url, "");
	} else if(window.external) { // IE Favourite
		window.external.AddFavorite(url, title);
        }
        else {
                return true;
        }
 }