// holds an instance of XMLHttpRequest
var xmlHttp_updatecart = createXmlHttpRequestObject();
// creates an XMLHttpRequest instance
function createXmlHttpRequestObject()
{
// will store the reference to the XMLHttpRequest object
var xmlHttp_updatecart;
// this should work for all browsers except IE6 and older
try
{
// try to create xmlHttp_updatecartRequest object
xmlHttp_updatecart = new XMLHttpRequest();
}
catch(e)
{
// assume IE6 or older
try
{
xmlHttp_updatecart = new ActiveXObject("Microsoft.XMLHttp");
}
catch(e) { }
}
// return the created object or display an error message
if (!xmlHttp_updatecart)
alert("Error creating the XMLHttpRequest object.");
else
return xmlHttp_updatecart;
}
	// called to read a file from the server
	
	 
	
	function updatecart()
	{
 		
		 var count = document.getElementById("count").value;
		var totalupdate = '';
		var qty= '';
		var id = '';
		for(var i=1;i<=count;i++)
		{
			id = document.getElementById("cartid"+i).value;
			qty = document.getElementById("qty"+i).value;	
			totalupdate = totalupdate+id+"-"+qty+",";	
		}
 
		 var url = "updatecart.php?totalupdate="+totalupdate;
		 
		if (xmlHttp_updatecart)
		{
		// try to connect to the server
			try
			{
			
			xmlHttp_updatecart.open("POST", url, true);
			xmlHttp_updatecart.onreadystatechange = handleRequestStateChange_updatecart;
			xmlHttp_updatecart.send(null);
			}
			// display the error in case of failure
			catch (e)
			{
			alert("Can't connect to server:\n" + e.toString());
			}
	 
		
		}
	
	}
	
	
	
	
	
	
	// function that handles the HTTP response
	function handleRequestStateChange_updatecart()
	{
	// obtain a reference to the <div> element on the page
	
	// display the status of the request
	if (xmlHttp_updatecart.readyState == 1)
	{
		
		
		//document.getElementById("default_tab").style.display="block";

	}/*
	else if (xmlHttp_updatecart.readyState == 2)
	{
	myDiv.innerHTML += "Request status: 2 (loaded) <br/>";
	}
	else if (xmlHttp_updatecart.readyState == 3)
	{
	myDiv.innerHTML += "Request status: 3 (interactive) <br/>";
	}
	// when readyState is 4, we also read the server response
	*/
	else if (xmlHttp_updatecart.readyState == 4)
	{
		// continue only if HTTP status is "OK"
 
		if (xmlHttp_updatecart.status == 200)
		{
				
			try
			{
			
				response = xmlHttp_updatecart.responseText;
				 
		 		//document.getElementById("cart").innerHTML = response;
			 	showcart();
			
			}
			catch(e)
			{
			// display error message
				alert("Error reading the response: " + e.toString());
			}
		}
		else
		{
			// display status message
		alert("There was a problem retrieving the data:\n" +
		xmlHttp_updatecart.statusText);
		}
		
	}
}