// 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 continent dropdown list
function DSCategoryOnChange() 
{
    var DSCategory = document.getElementById("DSCategory");
    
    // get selected continent from dropdown list
    var selectedContinent = DSCategory.options[DSCategory.selectedIndex].value;
    
    // 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.php" + "?filter=" + encodeURIComponent(selectedContinent);
    // use the following line if using php
    // requestUrl = "xml_data_provider.php" + "?filter=" + encodeURIComponent(selectedContinent);
    
//   alert(requestUrl);
	CreateXmlHttpObj();
	
	// verify XmlHttpObj variable was successfully initialized
	if(XmlHttpObj)
	{
//		alert("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 = StateChangeHandler;
		
		// 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 StateChangeHandler()
{
//	alert("readystate " + XmlHttpObj.readyState);
	// state ==4 indicates receiving response data from server is completed
	if(XmlHttpObj.readyState == 4)
	{
//		alert("readystate " + XmlHttpObj.status);
		// To make sure valid response is received from the server, 200 means response received is OK
		if(XmlHttpObj.status == 200)
		{			
//			alert("in 200:"+XmlHttpObj.responseXML.documentElement);
			PopulateDSSubCategory(XmlHttpObj.responseXML.documentElement);
		}
		else
		{
			alert("problem retrieving data from the server, status code: "  + XmlHttpObj.status);
		}
	}
}

// populate the contents of the country dropdown list
function PopulateDSSubCategory(countryNode)
{
//	alert("countryNode"+countryNode);
    var DSSubCategory = document.getElementById("DSSubCategory");
//	alert("DSSubCategory: "+DSSubCategory);
	// clear the country list 
	for (var count = DSSubCategory.options.length-1; count >-1; count--)
	{
		DSSubCategory.options[count] = null;
	}

	var countryNodes = countryNode.getElementsByTagName('country');
	var idValue;
	var textValue; 
	var optionItem;
	// populate the dropdown list with data from the xml doc
	for (var count = 0; count < countryNodes.length; count++)
	{
		textValue = GetInnerText(countryNodes[count]);
//		alert(textValue);
		idValue = countryNodes[count].getAttribute("id");
		optionItem = new Option( textValue, idValue,  false, false);
		DSSubCategory.options[DSSubCategory.length] = optionItem;
	}
}

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


function loadfiledesc(datasetid,exist)
{
   
    //alert(datasetid);
	datid=datasetid;
    var requestUrl;
    // use the following line if using asp
    requestUrl = "xml_datasetdetails_provider.php" + "?filter=" + datasetid +"&exist="+exist;
   
    
//   alert(requestUrl);
	CreateXmlHttpObj();
	
	// verify XmlHttpObj variable was successfully initialized
	if(XmlHttpObj)
	{
//		alert("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 = DetailsChangeHandler;
		
		// 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 DetailsChangeHandler()
{
//	alert("readystate " + XmlHttpObj.readyState);
	// state ==4 indicates receiving response data from server is completed
	if(XmlHttpObj.readyState == 4)
	{
//		alert("readystate " + XmlHttpObj.status);
		// To make sure valid response is received from the server, 200 means response received is OK
		if(XmlHttpObj.status == 200)
		{			
//			alert("in 200:"+XmlHttpObj.responseXML.documentElement);
			PopulateDetails(XmlHttpObj.responseXML.documentElement);
		}
		else
		{
			alert("problem retrieving data from the server, status code: "  + XmlHttpObj.status);
		}
	}
}

// populate the contents of the country dropdown list
function PopulateDetails(countryNode)
{
	//alert(XmlHttpObj.ResponseText);
	document.getElementById(datid).style.visibility='visible';
 	document.getElementById(datid).innerHTML=XmlHttpObj.responseText;
	document.getElementById(datid).style.width='400px';
	document.getElementById(datid).style.height='250px';
}


 function close(datasetid)
 {
 	document.getElementById(datasetid).style.visibility='visible';
	document.getElementById(datasetid).innerHTML='';
	document.getElementById(datasetid).style.width='0px';
	document.getElementById(datasetid).style.height='0px';
	document.getElementById(datasetid).style.border='0px';
 }