function openWindow(url, width, height)
{
   var new_window = window.open(url, 'w', 'toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=no,left=100,top=100,width=' + width + ',height=' + height);
}

function addToCart(product_id)
{
	var target='/kosik-do.php?id_product='+product_id;
	if(document.getElementById('velkost_'+product_id)!=null)
	{
		target+='&size='+document.getElementById('velkost_'+product_id).value;
	}
	document.location=target;
}