// declare a global  XMLHTTP Request object
var XmlHttpObj;

// create an instance of XMLHTTPRequest Object, varies with browser type, try for IE first then Mozilla
function CreateXmlHttpObj()
{
	// try creating for IE (note: we don't know the user's browser type here, just attempting IE first.)
	try
	{
		XmlHttpObj = new ActiveXObject("Msxml2.XMLHTTP");
	}
	catch(e)
	{
		try
		{
			XmlHttpObj = new ActiveXObject("Microsoft.XMLHTTP");
		} 
		catch(oc)
		{
			XmlHttpObj = null;
		}
	}
	// if unable to create using IE specific code then try creating for Mozilla (FireFox) 
	if(!XmlHttpObj && typeof XMLHttpRequest != "undefined") 
	{
		XmlHttpObj = new XMLHttpRequest();
	}
}

// called from onChange or onClick event of the market dropdown list
function ModelOnChange(thisid) 
{
    var model = document.getElementById("recip");
    
    // get selected continent from dropdown list
    //var selectedMarket = model.value;
    //alert(thisid);
    // url of page that will send xml data back to client browser
    var requestUrl;
    // use the following line if using asp
    //requestUrl = "xml_data_provider.asp" + "?filter=" + encodeURIComponent(selectedContinent);
    // use the following line if using php
     requestUrl = "optionsxml.php" + "?id=" + encodeURIComponent(thisid);
		//alert ("Requesting page: " + requestUrl);
    
	CreateXmlHttpObj();
	
	// verify XmlHttpObj variable was successfully initialized
	if(XmlHttpObj)
	{
        // assign the StateChangeHandler function ( defined below in this file)
        // to be called when the state of the XmlHttpObj changes
        // receiving data back from the server is one such change
		XmlHttpObj.onreadystatechange = ModelChangeHandler;
		
		// define the iteraction with the server -- true for as asynchronous.
		XmlHttpObj.open("GET", requestUrl,  true);
		
		// send request to server, null arg  when using "GET"
		XmlHttpObj.send(null);		
	}
}
// this function called when state of  XmlHttpObj changes
// we're interested in the state that indicates data has been
// received from the server
function ModelChangeHandler()
{
	// state ==4 indicates receiving response data from server is completed
	if(XmlHttpObj.readyState == 4)
	{
		// To make sure valid response is received from the server, 200 means response received is OK
		if(XmlHttpObj.status == 200)
		{			
			//alert("XML status is 200");
			PopulateNewProjectList(XmlHttpObj.responseXML.documentElement);
		}
		else
		{
			alert("There was a problem retrieving data from the server, status code: "  + XmlHttpObj.status);
		}
	}
}

// populate the contents of the project dropdown list
function PopulateNewProjectList(projectNode)
{
	//alert("Populating project list");
    var projectList = document.getElementById("interested");
	// clear the country list 
	//alert("Clearing project list");
	for (var count = projectList.options.length-1; count >-1; count--)
	{
		projectList.options[count] = null;
	}

	var projectNodes = projectNode.getElementsByTagName('thumb');
	var idValue;
	var textValue; 
	var optionItem;
	//alert(projectNodes.length);
	// populate the dropdown list with data from the xml doc
	//alert("Populating project list");
	optionItem = new Option( '', '',  false, false);
	projectList.options[projectList.length] = optionItem;
	for (var count = 0; count < projectNodes.length; count++)
	{
   	textValue = GetInnerText(projectNodes[count]);
		idValue = projectNodes[count].getAttribute("id");
		optionItem = new Option( idValue, idValue,  false, false);
		projectList.options[projectList.length] = optionItem;
	}
}
// returns the node text value 
function GetInnerText (node)
{
	 return (node.textContent || node.innerText || node.text) ;
}