// JavaScript Funktionen fuer den AJAX Support
// W. Balzer, 22.02.2007
// Utility
function $(id)   { return document.getElementById(id); }

// Erzeugen des HttpRequest Objekts
function cXHR() {
	try { return new ActiveXObject("Msxml2.XMLHTTP.4.0"); } catch(e) {}
	try { return new ActiveXObject("MSXML2.XMLHTTP.3.0"); } catch(e) {}
	try { return new ActiveXObject("MSXML2.XMLHTTP"); } catch(e) {}
	try { return new ActiveXObject("Microsoft.XMLHTTP"); } catch(e) {}
	try { return new XMLHttpRequest(); } catch(e) {}
	alert("XMLHttpRequest not supported");
	return null;
}

// Senden eines HttpRequests
function sXHRg(url, update_func, domid) {
	var xhr = cXHR();
	xhr.open("GET", url, true);
	xhr.onreadystatechange = function() {
		rXHR(xhr, update_func, domid);
	}
	xhr.setRequestHeader("Content-Type", "text/html;charset=ISO-8859-1");
	xhr.setRequestHeader("Pragma", "no-cache");
	xhr.setRequestHeader("Cache-Control", "no-cache");
	xhr.setRequestHeader("Expires", "0");
	xhr.send(null);
}

// Empfangen der Rueckgabe von einem HttpRequest
function rXHR(xhr, update_func, domid) {
	if (xhr.readyState == 4) {
		if (xhr.status == 200) {
			var header = xhr.getAllResponseHeaders();
			update_func(xhr.responseText, domid);
		} else {
			alert("Response with error" + xhr.status);
		}
	}
}

// Einfache AJAX Funktionen zum Senden und Empfangen
function get_ajax(domid, url) {
	sXHRg(url, set_ajax, domid);
}

function set_ajax(text, domid) {
	$(domid).innerHTML = text;
}