// global flag
var isIE = false;
// global request and XML document objects
var req;
// global intervall
var aktiv;
// global name of layer
var layerName;
// debug
var debug = false;

var tagName = '';
// invoked by "Category" select element change;
// loads chosen XML document, clears Topics select
// element, loads new items into Topics select element
function loadDoc(url) {
    try {
    	loadXMLDoc(url);
    }
    catch(e) {
        var msg = (typeof e == "string") ? e : ((e.message) ? e.message : "Unknown Error");
        if (debug == true)
        	alert("Unable to get XML data:\n" + msg);
        
        window.clearInterval(aktiv);
        writeToDiv('Error');
    }
     
}

// retrieve XML document (reusable generic function);
// parameter is URL string (relative or complete) to
// an .xml file whose Content-Type is a valid XML
// type, such as text/xml; XML source must be from
// same domain as HTML file
function loadXMLDoc(url) {
	// branch for native XMLHttpRequest object
    if (window.XMLHttpRequest) {
        req = new XMLHttpRequest();
        req.onreadystatechange = processReqChange;
        // req.overrideMimeType('text/xml; charset=utf-8');
        req.open("GET", url, true);
        req.send(null);
    // branch for IE/Windows ActiveX version
    } else if (window.ActiveXObject) {
        isIE = true;
        req = new ActiveXObject("Microsoft.XMLHTTP");
        if (req) {
            req.onreadystatechange = processReqChange;
            req.open("GET", url, true);
            req.send();
        }
    }
}


// handle onreadystatechange event of req object
function processReqChange() {
	// alert(tagName);
    // only if req shows "loaded"
    if (req.readyState == 4) {
        // only if "OK"
        // alert(req.getAllResponseHeaders());
        if (req.status == 200) {
        	if (tagName == 'textonly')
        	{
        	// Daten als Text empfangen
        	var Value = req.responseText;
        	}
        	else
        	{
        	
        	// Daten als XML-DOM empfangen
        	var Tag = req.responseXML.getElementsByTagName(tagName).item(0);
        	var Value = Tag.firstChild.nodeValue;
			// var data = req.responseXML.getElementsByTagName("time").item(0).data;
        	}
			writeToDiv(Value);
        	
         } else {
         	if (debug == true)
            	alert("There was a problem retrieving the XML data:\n" + req.status + " " + req.statusText);
            
            window.clearInterval(aktiv);
            writeToDiv('Error');
         }
    }
}


function writeToDiv(text) {
	div = document.getElementById(layerName);
    div.innerHTML = "";
    // blast new HTML content into "details" <div>
    div.innerHTML = text;
	// alert(timeValue);
}


function getURLData(url, interval, writeTo, xmlTagName) {
	// 2006-11-02 Layer wb_detail bei einem neuen Buchstaben leeren...
	if (writeTo == "wb_list")
		document.getElementById("wb_detail").innerHTML = "";
	
	layerName = writeTo;
	tagName = xmlTagName;
	if (interval > 0) {
		// Zeit in Millisekunden
		interval = interval * 1000;
		aktiv = window.setInterval("loadDoc('"+url+"');", interval);
	} else 
		aktiv = null;
	loadDoc(url);
}