var http_request = false;

    function macheRequest(url) {

        http_request = false;

        if (window.XMLHttpRequest) { // Mozilla, Safari,...
            http_request = new XMLHttpRequest();
            if (http_request.overrideMimeType) {
                http_request.overrideMimeType('text/xml');
                // zu dieser Zeile siehe weiter unten
            }
        } else if (window.ActiveXObject) { // IE
            try {
                http_request = new ActiveXObject("Msxml2.XMLHTTP");
            } catch (e) {
                try {
                    http_request = new ActiveXObject("Microsoft.XMLHTTP");
                } catch (e) {}
            }
        }

        if (!http_request) {
            alert('Ende :( Kann keine XMLHTTP-Instanz erzeugen');
            return false;
        }
        http_request.onreadystatechange = alertInhalt;
        http_request.open('GET', url, true);
		http_request.setRequestHeader("Pragma", "no-cache");
		http_request.setRequestHeader("Cache-Control", "must-revalidate");
		http_request.setRequestHeader("If-Modified-Since", document.lastModified);
        http_request.send(null);

    }

	
    var http_request1 = false;

    function macheRequest1(url) {

        http_request1 = false;

        if (window.XMLHttpRequest) { // Mozilla, Safari,...
            http_request1 = new XMLHttpRequest();
            if (http_request1.overrideMimeType) {
                http_request1.overrideMimeType('text/xml');
                // zu dieser Zeile siehe weiter unten
            }
        } else if (window.ActiveXObject) { // IE
            try {
                http_request1 = new ActiveXObject("Msxml2.XMLHTTP");
            } catch (e) {
                try {
                    http_request1 = new ActiveXObject("Microsoft.XMLHTTP");
                } catch (e) {}
            }
        }

        if (!http_request1) {
            alert('Ende :( Kann keine XMLHTTP-Instanz erzeugen');
            return false;
        }
        http_request1.onreadystatechange = alertInhalt;
        http_request1.open('GET', url, true);
		http_request1.setRequestHeader("Pragma", "no-cache");
		http_request1.setRequestHeader("Cache-Control", "must-revalidate");
		http_request1.setRequestHeader("If-Modified-Since", document.lastModified);
        http_request1.send(null);

    }

	
    var http_request2 = false;

    function macheRequest2(url) {

        http_request2 = false;

        if (window.XMLHttpRequest) { // Mozilla, Safari,...
            http_request2 = new XMLHttpRequest();
            if (http_request2.overrideMimeType) {
                http_request2.overrideMimeType('text/xml');
                // zu dieser Zeile siehe weiter unten
            }
        } else if (window.ActiveXObject) { // IE
            try {
                http_request2 = new ActiveXObject("Msxml2.XMLHTTP");
            } catch (e) {
                try {
                    http_request2 = new ActiveXObject("Microsoft.XMLHTTP");
                } catch (e) {}
            }
        }

        if (!http_request2) {
            alert('Ende :( Kann keine XMLHTTP-Instanz erzeugen');
            return false;
        }
        http_request2.onreadystatechange = alertInhalt;
        http_request2.open('GET', url, true);
		http_request2.setRequestHeader("Pragma", "no-cache");
		http_request2.setRequestHeader("Cache-Control", "must-revalidate");
		http_request2.setRequestHeader("If-Modified-Since", document.lastModified);
        http_request2.send(null);

    }
	
    var http_request3 = false;

    function macheRequest3(url) {

        http_request3 = false;

        if (window.XMLHttpRequest) { // Mozilla, Safari,...
            http_request3 = new XMLHttpRequest();
            if (http_request3.overrideMimeType) {
                http_request3.overrideMimeType('text/xml');
                // zu dieser Zeile siehe weiter unten
            }
        } else if (window.ActiveXObject) { // IE
            try {
                http_request3 = new ActiveXObject("Msxml2.XMLHTTP");
            } catch (e) {
                try {
                    http_request3 = new ActiveXObject("Microsoft.XMLHTTP");
                } catch (e) {}
            }
        }

        if (!http_request3) {
            alert('Ende :( Kann keine XMLHTTP-Instanz erzeugen');
            return false;
        }
        http_request3.onreadystatechange = alertInhalt;
        http_request3.open('GET', url, true);
		http_request3.setRequestHeader("Pragma", "no-cache");
		http_request3.setRequestHeader("Cache-Control", "must-revalidate");
		http_request3.setRequestHeader("If-Modified-Since", document.lastModified);
        http_request3.send(null);

    }


    function alertInhalt() {

        if (http_request.readyState == 4) {
              //  alert(http_request.responseText);
		document.getElementById("content_front").innerHTML = http_request.responseText;
        }
		if (http_request1.readyState == 4) {
              //  alert(http_request.responseText);
		document.getElementById("menu_bottom").innerHTML = http_request1.responseText;
        }
		  if (http_request2.readyState == 4) {
              //  alert(http_request.responseText);
		document.getElementById("top_nav").innerHTML = http_request2.responseText;
        }
		 if (http_request3.readyState == 4) {
              //  alert(http_request.responseText);
		document.getElementById("content_back").innerHTML = http_request3.responseText;
        }
    }