function menuRequest(url) {
    var arg = url;
    url = "content.php?q=" + url;
    var http_request = false;

    if (window.XMLHttpRequest) { // Mozilla, Safari,...
        http_request = new XMLHttpRequest();
        if (http_request.overrideMimeType){
            http_request.overrideMimeType('text/xml');  // See note below about this line
        }
    } 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('Giving up :( Cannot create an XMLHTTP instance');
        return false;
    }
    http_request.onreadystatechange = function() { alertContents(http_request); };
    http_request.open('GET', url, true);
    http_request.send(null);
}

function alertContents(http_request) {
    if (http_request.readyState == 4) {
        if (http_request.status == 200) {
            document.getElementById("content").innerHTML=http_request.responseText;
        } else {
            alert('There was a problem with the request.');
        }
    }
}