function getXmlHttpRequestObject()
{
	if (window.XMLHttpRequest)
	{
		// code for IE7+, Firefox, Chrome, Opera, Safari
		return new XMLHttpRequest();
	}

	else if (window.ActiveXObject)
	{
		// code for IE6, IE5
		return new ActiveXObject('Microsoft.XMLHTTP');
	}

	else
	{
		alert ('Browser does not support HTTP Request');
		return null;
	}
}

var sendReq = getXmlHttpRequestObject();

function toggleLight(action, path, id)
{
	var img	= document.getElementById(id);
	var src = '/pics/' + path + '/';

	if (action == 1)
	{
		img.src = src + id + '_hover.gif';
	}
	else
	{
		img.src = src + id + '.gif';
	}
}

function updateProd(action)
{
	var numb		= document.getElementById('numb');
	var btn_minus	= document.getElementById('minus');
	var btn_plus	= document.getElementById('plus');

	if (action == 'minus')
	{
		(numb.value > 0) ? numb.value-- : numb.value = 0;
	}
	else if (action == 'plus')
	{
		(numb.value >= 0) ? numb.value++ : numb.value = 0;
	}

	if (numb.value <= 0)
	{
		btn_minus.disabled = true;
	}
	else
	{
		btn_minus.disabled = false;
	}
}

function updateCart(id, stock, price, action)
{
	var numb			= document.getElementById('numb[' + id + ']');
	var btn_minus		= document.getElementById('minus[' + id + ']');
	var btn_plus		= document.getElementById('plus[' + id + ']');

	if (action == 'minus')
	{
		if (numb.value > 0)
		{
			numb.value--;
		}
		else
		{
			numb.value = 0;
		}

		(numb.value < stock) ? '' : numb.value = stock;

	}
	else if (action == 'plus')
	{
		(numb.value >= 0) ? '' : numb.value = 0;

		if (numb.value < stock)
		{
			numb.value++;
		}
		else
		{
			numb.value = stock;
		}
	}

	if (numb.value <= 0)
	{
		btn_minus.disabled = true;
	}
	else
	{
		btn_minus.disabled = false;
	}
	
	if (numb.value >= stock)
	{
		btn_plus.disabled = true;
	}
	else
	{
		btn_plus.disabled = false;
	}

	if (sendReq.readyState == 4 || sendReq.readyState == 0)
	{
		sendReq.open('POST', '/javascript/cart.php', true);
		sendReq.setRequestHeader('Content-Type','application/x-www-form-urlencoded');

		var param		=	'id='		+ id;
		param			+=	'&numb='	+ numb.value;
		param			+=	'&action='	+ action;		

		sendReq.send(param);
	}
}