function elm(id) { return document.getElementById(id); }

function newXMLHttpRequest()
{
	if( !window.XMLHttpRequest )
	{
	  try{ return new ActiveXObject("Msxml2.XMLHTTP.6.0") }catch(e){}
	  try{ return new ActiveXObject("Msxml2.XMLHTTP.3.0") }catch(e){}
	  try{ return new ActiveXObject("Msxml2.XMLHTTP") }catch(e){}
	  try{ return new ActiveXObject("Microsoft.XMLHTTP") }catch(e){}
	  throw new Error("XMLHttpRequest seçeneği yok.")
	};
	return new XMLHttpRequest();
}

function ajax(url, elmId)
{
	var request = newXMLHttpRequest();
	request.onreadystatechange = function()
	{
		if (request.readyState == 4 && request.status == 200)
		{
			elm(elmId).innerHTML = request.responseText;
		}
	};
	request.open("GET", url, true);
	request.send(null);
}

function updateVisibleCarts()
{
	if (elm("cartS") != null)
		ajax("cart.php?show=small","cartS");
	if (elm("cartL") != null)
		ajax("cart.php?show=large","cartL");
	if (elm("cartSum") != null)
		ajax("cart.php?show=summary","cartSum");
}

function addToCart(id, amount)
{
	ajax("cart.php?action=add&id="+id+"&amount="+amount+"&show=small","cartS");
	updateVisibleCarts();
}

function updateCart(id, amount)
{
	ajax("cart.php?action=update&id="+id+"&amount="+amount+"&show=small","cartS");
	updateVisibleCarts();
}

function deleteFromCart(id)
{
	if (confirm("Emin misiniz?"))
	{
		ajax("cart.php?action=delete&id="+id+"&show=small","cartS");
		updateVisibleCarts();
	}
}

function emptyCart()
{
	if (confirm("Sepetteki tüm ürünler silinecek. Emin misiniz?"))
	{
		ajax("cart.php?action=empty&show=small","cartS");
		updateVisibleCarts();
	}
}