//Global XMLHTTP Request object
var XmlHttp;

//Creating and setting the instance of appropriate XMLHTTP Request object to a “XmlHttp” variable  
function CreateXmlHttp()
{
	//Creating object of XMLHTTP in IE
	try
	{
		XmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
	}
	catch(e)
	{
		try
		{
			XmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
		} 
		catch(oc)
		{
			XmlHttp = null;
		}
	}
	//Creating object of XMLHTTP in Mozilla and Safari 
	if(!XmlHttp && typeof XMLHttpRequest != "undefined") 
	{
		XmlHttp = new XMLHttpRequest();
	}
}

//Gets called when country combo box selection changes
function CountryListOnChange() 
{
	var countryList = document.getElementById("countryList");

	//Getting the selected country from country combo box.
	var selectedCountry = countryList.options[countryList.selectedIndex].value;
	
	countryList.options[countryList.selectedIndex].selected=true;
	if(selectedCountry=="Others")
	{
		document.getElementById("d1").style.display = "none";
		document.getElementById("d2").style.display = "block";
	}
	else
	{
	document.getElementById("d1").style.display = "block";
	document.getElementById("d2").style.display = "none";
	
	
	// URL to get states for a given country
	var requestUrl = AjaxServerPageName + "?SelectedCountry=" + encodeURIComponent(selectedCountry);
	//alert(requestUrl);
	CreateXmlHttp();
	
	// If browser supports XMLHTTPRequest object
		if(XmlHttp)
		{
			//Setting the event handler for the response
			XmlHttp.onreadystatechange = HandleResponse;
			
			//Initializes the request object with GET (METHOD of posting), 
			//Request URL and sets the request as asynchronous.
			XmlHttp.open("GET", requestUrl,  true);
			
			//Sends the request to server
			XmlHttp.send(null);		
		}
	}
}


//Called when response comes back from server
function HandleResponse()
{
	// To make sure receiving response data from server is completed
	if(XmlHttp.readyState == 4)
	{
		// To make sure valid response is received from the server, 200 means response received is OK
		if(XmlHttp.status == 200)
		{			
			ClearAndSetStateListItems(XmlHttp.responseXML.documentElement);
		}
		else
		{
			alert("There was a problem retrieving data from the server." );
		}
	}
}

//Clears the contents of state combo box and adds the states of currently selected country
function ClearAndSetStateListItems(countryNode)
{
	var stateList = document.getElementById("stateList");
	//Clears the state combo box contents.
	for (var count = stateList.options.length-1; count >-1; count--)
	{
		stateList.options[count] = null;
	}
	
	var stateNodes = countryNode.getElementsByTagName('state');
	var textValue; 
	var optionItem;
	//Add new states list to the state combo box.
	for (var count = 0; count < stateNodes.length; count++)
	{
   		textValue = GetInnerText(stateNodes[count]);
		optionItem = new Option( textValue, textValue,  false, false);
		stateList.options[stateList.length] = optionItem;
	}
}

//Returns the node text value 
function GetInnerText (node)
{
	 return (node.textContent || node.innerText || node.text) ;
}