//here you place the ids of every element you want.
var ids=new Array('details','features','location','seller_info');

function switchid(id)
{
	hideallids();
	showdiv(id);
}

function hideallids()
{
	//loop through the array and hide each element by id
	for (var i=0;i<ids.length;i++){
		hidediv(ids[i]);
	}		  
}

function hidediv(id)
{
	//safe function to hide an element with a specified id
	if (document.getElementById) { // DOM3 = IE5, NS6
		document.getElementById(id).style.display = 'none';
	} else {
		if (document.layers) { // Netscape 4
			document.id.display = 'none';
		} else { // IE 4
			document.all.id.style.display = 'none';
		}
	}
}

function showdiv(id)
{
	//safe function to show an element with a specified id
	if (document.getElementById) { // DOM3 = IE5, NS6
		document.getElementById(id).style.display = 'block';
	} else {
		if (document.layers) { // Netscape 4
			document.id.display = 'block';
		} else { // IE 4
			document.all.id.style.display = 'block';
		}
	}
}

// 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();
	}
}

function getModel(makeListId)
{
	makeListFormId = makeListId;
	var makeList = document.getElementById(makeListId);
	var selectedMake = makeList.options[makeList.selectedIndex].value;
	var requestUrl;
	requestUrl = "xml_data_provider.php" + "?filter=" + encodeURIComponent(selectedMake);

	CreateXmlHttpObj();
	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);		
	}
}

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

// populate the contents of the dropdown list
function populateModelList(modelNode)
{
	if(makeListFormId == 'makeSideList') {
		var modelFormId = 'modelSideList';
	} else if(makeListFormId == 'makeSearchList') {
		var modelFormId = 'modelSearchList';
	} else if(makeListFormId == 'makeIndexList') {
		var modelFormId = 'modelIndexList';
	}

    var modelList = document.getElementById(modelFormId);

	// clear the list 
	for (var count = modelList.options.length-1; count >-1; count--) {
		modelList.options[count] = null;
	}

	var modelNode = modelNode.getElementsByTagName('model');
	var idValue;
	var textValue; 
	var optionItem;
	
	// populate the dropdown list with data from the xml doc
	for (var count = 0; count < modelNode.length; count++) {
   		textValue = GetInnerText(modelNode[count]);
		idValue = modelNode[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) ;
}