// 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 tip dropdown list
function tipListOnChange() 
{
    var tipList = document.getElementById("tipList");
    
    // get selected tip from dropdown list
    var selectedtip = tipList.options[tipList.selectedIndex].value;
    
       // use the following line if using php
     requestUrl = "http://www.automobiletv.ro/2hd/marci.php" + "?sel=1" + "&filter=" + encodeURIComponent(selectedtip);
    
	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 = 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);		
	}
}



// called from onChange or onClick event of the marca dropdown list
function marcaListOnChange() 
{
    var marcaList = document.getElementById("marcaList");
    
    // get selected marca from dropdown list
    var selectedmarca = marcaList.options[marcaList.selectedIndex].value;
	
    
    // url of page that will send xml data back to client browser
    var requestUrl;
        // use the following line if using php
     requestUrl = "http://www.automobiletv.ro/2hd/marci.php" + "?sel=2" + "&filter=" + encodeURIComponent(selectedmarca);
	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 = StatesChangeHandler;
		
		// 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()
{
	// 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)
		{			
	PopulateMarcaList(XmlHttpObj.responseXML.documentElement);
		}
		else
		{
			alert("problem retrieving data from the server, status code: "  + XmlHttpObj.status);
		}
	}
}


function StatesChangeHandler()
{
	// 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)
		{			
	PopulatemodelList(XmlHttpObj.responseXML.documentElement);
		}
		else
		{
			alert("problem retrieving data from the server, status code: "  + XmlHttpObj.status);
		}
	}
}



// populate the contents of the marca dropdown list
function PopulateMarcaList(marcaNode)
{
    var marcaList = document.getElementById("marcaList");
    var modelList = document.getElementById("modelList");
	// clear the marca list 
	for (var count = marcaList.options.length-1; count >-1; count--)
	{
		marcaList.options[count] = null;
	}


	for (var count = modelList.options.length-1; count >-1; count--)
	{
		modelList.options[count] = null;
	}
	marcaList.options[0] = new Option("Selecteaza...", "0", false, false);

	modelList.options[0] = new Option("Selecteaza...", "0", false, false);

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



function PopulatemodelList(modelNode)
{
    var modelList = document.getElementById("modelList");
	// clear the model list 
	for (var count = modelList.options.length-1; count >-1; count--)
	{
		modelList.options[count] = null;
	}

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


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