//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 ListOnChange(i) 
{
 setVariables(i);
 //alert(AjaxServerPageName + "\n" + PrimaryID + "\n" + SecondaryID + "\n" + ElementsByTagName);
	var pList = document.getElementById(PrimaryID);

	//Getting the selected country from country combo box.
	var selectedValue = pList.options[pList.selectedIndex].value;
	
	// URL to get states for a given country
	var requestUrl = AjaxServerPageName + "item=" + encodeURIComponent(selectedValue);
	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(itemNode)
{
    var sList = document.getElementById(SecondaryID);
	//Clears the state combo box contents.
	for (var count = sList.options.length-1; count >-1; count--)
	{
		sList.options[count] = null;
	}

	var sNodes = itemNode.getElementsByTagName(ElementsByTagName);
	var textValue; 
	var optionItem;
	//Add new states list to the state combo box.
	if(sNodes.length > 0)
	{ sList.disabled = false;
	  optionItem = new Option(DefaultText, DefaultValue, false, false);
	  sList.options[sList.length] = optionItem;
  	for (var count = 0; count < sNodes.length; count++)
	  {
   		textValue = GetInnerText(sNodes[count]);
		   optionItem = new Option( textValue, textValue, false, false);
		   sList.options[sList.length] = optionItem;
	  }
	}
	else
	{ sList.disabled = true;
	  optionItem = new Option(DefaultText, DefaultValue,   false, false);
	  sList.options[sList.length] = optionItem;
	}
}

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